Certain 4-thia-2,6-diazabicyclo(3.2.0)heptane derivatives

ABSTRACT

THE INVENTION CONCERNS COMPOUNDS OF THE FORMULA   2-R2&#34;,3-R5,3-R6,6-(RA&#39;&#39;-P(-RB&#39;&#39;)(-RC&#39;&#39;)=C(-COO-R1A&#39;&#39;)-),7-(O=)   -4-THIA-2,6-DIAZABICYCLO(3.2.0)HEPTANE   IN WHICH R1A&#39;&#39; IS LOWER ALKYL, HALOGENO-LOWER ALKYL, CYCLOALKYL OR PHENYL-LOWER ALKYL, R2&#34; IS AN ACYL RADICALS, EACH OF R5 AND R6 IS LOWER ALKYL, AND EACH OF RA&#39;&#39;, RB&#39;&#39; AND RC&#39;&#39; IS LOWER ALKYL OR PHENYL. THESE COMPOUNDS ARE INTERMEDIATES FOR THE MANUFACTURE OF CEPH-3-EM-4-CARBOXYLIC ACID COMPOUNDS.

United States Patent 3,799,938 CERTAIN 4-THIA-2,6-DIAZABICYCLO [3.2.0]HEPTANE DERIVATIVES Karl Heusler, Basel, Switzerland, and Robert Burns Woodward, Cambridge, Mass., assignors to Ciba-Geigy Corporation No Drawing. Original application July 22, 1969, Ser. No. 843,754. Divided and this application June 29, 1971, Ser. No. 158,083

Claims priority, application Switzerland, July 23, 1968, 10,994/68, 10,995/68, 10,996/68; Dec. 11, 1968, 18,502/68, 18,503/68, 18,505/ 68 Int. Cl. C07d 99/24 US. Cl. 260306.7 5 Claims ABSTRACT OF THE DISCLOSURE The invention concerns compounds of the formula COORIAI R, O=CN/ P R H &H R, R2"N S R5 Rt in which R is lower alkyl, halogeno-lower alkyl, cycloalkyl or phenyl-lower alkyl, R is an acyl radical, each of R and R is lower alkyl, and each of R R and R is lower alkyl or phenyl. These compounds are intermediates for the manufacture of ceph-3-em-4-carboxylic acid compounds.

CROSS REFERENCE TO RELATED APPLICATION This is a divisional of co-pending Ser. No. 843,754, filed July 22, 1969.

The subject of the present invention is oc-hydroxy- 2-oxo-l-azatidinemethane-carboxylic acid compounds of formula wherein R represents a hydrogen atom or the organic residue of an alcohol, R represents a hydrogen atom or an acyl residue, R represents an organic residue and R represents a hydrogen atom, when R stands for an acyl residue, or the two groups R;, and R together represent a disubstituted carbon atom, when R stands for a hydrogen atom or an acyl group, as well as salts of such compounds having salt-forming groupings.

The group R, can denote the organic residue of any alcohol, but especialy an optionally substituted aliphatic or araliphatic hydrocarbon residue.

An acyl group R primarily represents the acyl residue of an organic carboxylic acid, especially of a carbonic acid semi-derivative or of an optionaly substituted aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, aromatic, araliphatic, heterocyclic or heterocyclic-aliphatic carboxylic acid.

An organic residue R is an optionally substituted hydrocarbon residue, primarily an aliphatic hydrocarbon residue which can be split off and is preferably unsaturated, or substituted by a hetero-residue, in the linkage position,

as well as an appropriate cycloaliphatic, cycloaliphaticaliphatic or araliphatie hydrocarbon residue which is preferably unsaturated or substituted by a hetero-residue in the linkage position.

Substituents of a disubstituted carbon atom which is represented by the two residues R and R together are optionally substituted hydrocarbon residues, such as optionally substituted aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, aromatic or araliphatic hydrocarbon residues. The two substituents of the disubstituted carbon atom can also be taken together and can, for example, represent a bivalent aliphatic hydrocarbon residue which is optionally substituted and/or interrupted by hetero atoms.

An aliphatic hydrocarbon residue is an alkyl, alkenyl or alkynyl residue, especially a lower alkyl or lower alkenyl as well as a lower al'kynyl residue, which can, for example, contain up to 7, preferably up to 4, carbon atoms. Such residues can optionally be monosubstituted, disubstituted or polysubstituted by functional groups, for example, by etherified or esterified hydroxyl or mercapto groups, such as lower alkoxy, lower alkenyloxy, lower alkylenedioxy, optionally substituted phenyloxy or phenyllower alkoxy, lower alkylmercapto or optionally substituted phenylmercapto or phenyl-lower alkyl-mercapto, lower alkoxycarbonyloxy or lower alkanoyloxy groups, as well as by halogen atoms, and, furthermore, by acyl residues of organic carboxylic acids, nitro groups, optionally substituted amino groups and/or optionally functionally modified carboxyl groups, such as carbo-lower alkoxy, optionally N-substituted carbamoyl or cyano groups.

Cycloaliphatic or cycloaliphatic-aliphatic hydrocarbon residues are, for example, monocyclic, bicyclic or polycyclic cycloalkyl or cycloalkenyl groups and cycloalkylor cycloalkenyl-lower alkyl or -lower alkenyl groups, respectively, wherein cycloalkyl residues, for example, contain up to 12, such as 3-8, preferably 3-6, ring carbon atoms, while cycloalkenyl residues, for example, contain up to 12, for example, 3-8, especially 5-8, preferably 5 or 6 ring carbon atoms, as well as 1 to 2 double bonds, and the aliphatic portion of a cycloaliphatic-aliphatic residue can, for example, contain up to 7, preferably up to 4 carbon atoms. The above cycloaliphatic or cycloaliphatic-aliphatic residues can, if desired, be monosubstituted, disubstituted or polysubstituted, for example, by optionally substituted aliphatic hydrocarbon residues, such as, for example, the optionally substituted lower alkyl groups mentioned above, or by functional groups, e.g. like the above-mentioned aliphatic hydrocarbon residues.

An aromatic hydrocarbon residue is, for example, a monocyclic or bicyclic aromatic hydrocarbon residue, especially a phenyl residue, as well as a biphenylyl or naphthyl residue, which can optionally be monosubstituted, disubstituted or poysubstituted, for example, like the above-mentioned aliphatic and cycloaliphatic hydrocarbon residues.

An araliphatic hydrocarbon residue is an aliphatic hydrocarbon residue, which is optionally substituted and which, for example, possesses up to three optionally substituted monocyclic or bicyclic aromatic hydrocarbon residues, and primarily represents a phenyl-lower alkyl or phenyl-lower alkenyl, as well as phenyl-lower alkinyl residue, which residues contain 1-3 phenyl groups and can optionally 'be monosubstituted, disubstituted or polysubstituted in the aromatic and/ or aliphatic portion, for example, like the above-mentioned aliphatic and cycloaliphatic residues.

A bivalent aliphatic hydrocarbon residue is primarily a lower alkylene as well as a lower alkyenylene residue which, for example, contains up to 8, preferably 4 to 5,

3 carbon atoms and which can be substituted, if desired, for example, like the above mentioned cycloaliphatic residues.

The heterocyclic portion of a heterocyclic or heterocyclic-aliphatic residue is especially a monocyclic, as well as bicyclic or polycyclic, azacyclic, thiacyclic, oxacyclic, thiazacyclic, oxazacyclic or diazacyclic residue of aromatic character which can optionally be monosubstituted, disubstituted or polysubstituted, for example, like the above-mentioned cycloaliphatic residues. The aliphatic portion in heterocyclic-aliphatic residues may, for example, possess the substituents listed for the corresponding cycloaliphatic-aliphatic or araliphatic residues.

The acyl residue of a carbonic acid semi-derivative is preferably the acyl residue of a corresponding halfester, wherein the esterifying organic residue represents an optionally substituted aliphatic, cycloaliphatic, aromatic or araliphatic hydrocarbon residue or a heterocyclic-aliphatic residue, primarily the residue of an optionally substituted lower alkyl half-ester of carbonic acid (i.e. a carbo-Iower al koxy residue which is optionally substituted in the lower alkyl portion), as well as a lower alkenyl, cycloalkyl, phenyl or phenyl-lower alkyl halfester of carbonic acid, which may optionally be substituted in the lower alkenyl, cycloalkyl, phenyl and phenyl-lower alkyl portion respectively (i.e. a carbolower alkenyloxy, carbo-cycloalkoxy, carbo-phenyloxy or carbo-phenyl-lower alkoxy residue which is optionally substituted in the lower alkenyl, cycloalkyl, phenyl and phenyl-lower alkyl portion, respectively). Acyl residues of a carbonic acid half-ester are furthermore acyl residues of lower alkyl half-esters of carbonic acid, in which the lower alkyl portion contains a heterocyclic group, for example, one of the above-mentioned heterocyclic groups of aromatic character, the lower alkyl residue and the heterocyclic group being optionally substituted. Such acyl residues are carbo-lower alkoxy groups containing in the lower alkyl residue a heterocyclic group of aromatic character and being optionally substituted in the lower alkyl portion and in the heterocyclic group; heterocyclic groups of this nature are described in more detail below.

The acyl residue of an aliphatic carboxylic acid is, for example, the corresponding residue of an alkanecarboxylic, as well as alkenecarboxylic or alkynecarboxylic acid, primarily lower alkanecarboxylic, as well as lower alkenecarboxyic or lower alkynecarboxylic acid, which is optionally substituted, for example, like the above-mentioned aliphatic hydrocarbon residues and which can, for example, contain up to 7, especially up to 4, carbon atoms.

The acyl residue of a cycloaliphatic or cycloaliphaticaliphatic carboxylic acid is, for example, the acyl residue of a cycloalkaneor cycloalkenecarboxylic acid and cycloalkylor cycloalkenyl-lower alkaneor -lower alkenecarboxylic acid, respectively, which is optionally substituted, for example, like the above-mentioned cycloaliphatic or cycloaliphatic-aliphatic hydrocarbon residues, a cycloalkyl or cycloalkenyl residue as well as the aliphatic portion of a cycloaliphatic-aliphatic carboxylic acid having, for example the number of carbon atoms and/or double bonds specified above for corresponding residues and being optionally substituted, for example, as indicated.

The acyl residue of an aromatic carboxylic acid is primarily the residue of a monocyclic or bicyclic aromatic carboxylic acid which can optionally be substituted, for example, like the above -mentioned cycloaliphatic residue.

In the acyl residue of an araliphatic carboxylic acid the araliphatic portion, for example, has the above-mentioned significance; an araliphatic carboxylic acid primarily denotes a phenyl-lower alkanecarboxylic or phenyl-lower al-kenecarboxylic acid, wherein the phenyl residue and the aliphatic portion can optionally be substituted, for example, like the above-mentioned cycloaliphatic or alipathic groups.

The acyl residue of a heterocyclic carboxylic acid contains especially a heterocyclic residue of aromatic characteristics, which can. be monocyclic or bicyclic and primarily represents a corresponding monocyclic or bicyclic, monoazacyclic, monooxacyclic, monothiacyclic, diazacyclic, oxazacyclic or thiazacyclic residue which is optionally substituted, for example, like the above-mentioned cycloaliphatic residue. In the residue of a heterocyclicaliphatic carboxylic acid, the heterocyclic residue has the significance given above, while the aliphatic portion like, for example, in an araliphatic carboxylic acid, represents an optionally substituted lower alkyl as well as lower alkenyl residue.

A lower alkyl residue is for example, a methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert.- butyl as well as n-pentyl, isopentyl, n-hexyl, isohexyl or n-heptyl group, while a lower alkenyl residue can, for example, be a vinyl, allyl, isopropenyl, 2- or 3-methallyl or 3-butenyl group, and a lower alkynyl residue can, for example, be a propargyl or Z-butynyl group.

Optionally substituted aliphatic hydrocarbon residues, especially lower alkyl groups, which can, inter alia, also be substituents of cycloaliphatic, cycloaliphatic, aliphatic, aromatic, araliphatic, heterocyclic or heterocyclic-aliphatic residues, contain, for example, the above-mentioned substituents. Such substituted groups are especially halogenolower alkyl groups, such as monohalogenated, dihalogenated or polyhalogenated lower alkyl, for example, methyl, ethyl or 1- or 2-propyl groups; residues of this type, especially 2-halogeno-lower alkyl residues, such as 2,2,2- trichloroethyl or 2-iodoethyl groups, primarily represent halogenated lower alkyl residues R Other substituted aliphatic hydrocarbon residues, such as aliphatic hydrocarbon residues R which are substituted by hetero-residues in the linkage position, are primarily lower alkyl, such as methyl, ethyl, propyl or isopropyl residues containing in the linkage position etherified or esterified hydroxyl groups, for example, lower alkoxy or lower alkanoyloxy groups or halogen atoms. These, as well as aliphatic hydrocarbon residues R which are unsaturated in the linkage position, especially the 2-propenyl residue, can preferably be split off under acidic conditions, an alkanoyloxy group also being cleaved off under alkaline conditions, as well as by treatment with heavy metal salts, such as mercury or cadmium salts, capable of forming mercaptides, for example, the corresponding halides or lower alkanoyloxy compounds.

A cycloalkyl group is, for example, a cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl, as well as adamantyl group, and a cycloalkenyl group is, for example, a 2- or 3-cyclopentenyl, 1-, 2- or 3-cyclohexenyl or 3-cycloheptenyl, as well as Z-cyclopropenyl group. A cycloalkyl-lower alkyl or -lower alkenyl residue is, for example, a cyclopropyl-, cyclopentyl-, cyclohexylor cycloheptyl-methyl, -l,1-ethyl or -1,2-ethyl, -1,1-propy1, 1,2- propyl or -1,3-propyl, -vinyl or -allyl group, while a cycloalkenyl-lower alkyl or -lower alkenyl group, for example, represents a l-, 2- or 3-cyclopentyl-, 1-, 2- or 3-cyclohexenylor 1-, 2- or 3-cycloheptenyl-methyl, -1,1- ethyl or -1,2-ethyl, -1,1-propyl, -l,2-propyl or -1,3-propyl, -vinyl or -allyl group.

A naphthyl residue is a 1- or Z-naphthyl residue while a biphenylyl group represents, for example, a 4-biphenylyl residue.

A phenyl-lower alkyl or phenyl-lower alkenyl residue, is, for example, a benzyl, 1- or 2-phenylethyl, 1- or 2- or 3-phenylpropyl, diphenylmethyl, trityl, 1- or Z-naphthylmethyl, styryl or cinamyl residue.

A lower alkylene or lower alkenylene residue is, for example, represented by a 1,2-ethylene, 1,3-propylene, 2,2-dimethyl-1,3-propylene, 1,4-butylene, 1- or 2-methyl- 1,4-butylene, 1,4-dimethyl-l,4-butylene, 1,5-pentylene, 1-, 2- or 3-methyl-1,5-pentylene, 1,6-hexylene, 2-buten-l,4- ylene or 2- or 3-penten-1,5-ylene group.

Heterocyclic residues are, for example, monocyclic monoazacyclic, monothiacyclic or monooxacyclic residues of aromatic character, such as pyridyl, for example, Z-pyridyl, 3-pyridyl or 4-pyridyl residues, thienyl, for

example, 2-thienyl residues, or furyl, for example, Z-fu-ryl residues, or bicyclic monoazacyclic residues of aromatic character, such as quinolinyl, for example, 2-quino1inyl or 4-quinoliny1 residues, or isoquinolinyl, for example l-isoquinolinyl residues, or monocyclic thiazacyclic or oxazacyclic, as well as diacyclic residues of aromatic character, such as oxazolyl, iso-xazolyl, thiazolyl or isothiazolyl, as well as pyrimidinyl residues. Heterocyclicaliphatic residues are especially lower alkyl or lower alkenyl residues containing heterocyclic residues, such as those mentioned above.

Among the etherified hydroxyl groups there are primarily to be mentioned lower alkoxy groups, for example, methoxy, ethoxy, n-propyloxy, isopropyloxy, nbutyloxy, isobutyloxy, sec.-butyloxy, tert.-butyloxy, npentyloxy or tert.-pentyloxy groups, as well as substituted lower alkoxy groups, such as halogeno-lower alkoxy groups, especially 2-halogen-lower alkoxy groups, for example, 2,2,2-trichloroethoxy or 2-iodoethoxy groups, and, furthermore, lower alkenyloxy, for example, vinyloxy or allyloxy groups, lower alkylenedioxy, for example, methylenedioxy or ethylenedioxy, as well as isopropylidenedioxy groups, cycloalkoxy, for example, cyclopentyloxy, cyclohexyloxy or adamantyloxy groups, phenyloxy groups, phenyl-lower alkoxy, for example, benzyloxy or 1- or 2-phenylethoxy groups, or lower alkoxy groups which are substituted by monocyclic monoazacyclic, monooxacyclic or monothiacyclic groups of aromatic character, such as pyridyl-lower alkoxy, for example, 2- pyridylmethoxy, furyl-lowe'r alkoxy, for example, furfuryloxy, or thienyl-lower alkoxy, for example, 2-thenyloxy groups.

By etherified mercapto groups, lower alkylmercapto, for example, methylmercapto or ethylmercapto groups, phenylmercapto groups or phenyl-lower alkylmercapto, for example, benzylmercapto groups, are to be understood.

Esterified hydroxyl groups are primarily halogen atoms, for example, fluorine, chlorine, bromine or iodine atoms, as well as lower alkanoyloxy groups, for example, acetoxy or propionyloxy groups.

Substituted amino groups are monosubstituted or disubstituted amino groups, in which the substituents primarily present optionally substituted monovalent or divalent aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, aromatic or araliphatic hydrocarbon residues, as well as acyl groups. Such amino groups are especially lower alkylamino or di-lower alkylamino groups, for example, methylarnino, ethylamino, dimethylamino or diethylamino groups, or lower alkyleneamino groups, which are optionally interrupted by hetero-atoms, such as oxygen or sulphur atoms, or nitrogen atoms which are optionally substituted, for example, by lower alkyl groups, such as pyrrolidino, piperidino, morpholino, thiamorpholino or 4-methy1piperazino groups, as well as acylamino, particularly lower alkanoylamino, such as acetylamino or propionylamino groups.

A carbo-lower alkoxy residue is, for example, a carbomethoxy, carbethoxy, carbo-n-propyloxy, carbo-isopropyloxy, carbotert.-butyloxy or carbo-tert.pentyloxy group.

Optionally N-substituted carbamoyl groups are, for example, N-lower alkylcarbamoyl or N,N-di-lower alkylcarbamoyl groups, such as N-methyl-, N-ethyl, N,N-dimethyl or N,N-diethylcarbamoyl groups.

A carbo-lower alkenyloxy residue is, for example, the carbovinyloxy group, while carbo-cycloalkoxy and carbophenyl-lower alkoxy groups, in which the cycoalkylor phenyl-lower alkyl residue have the above-mentioned significance represent, for example, carbo-adamantyloxy or carbo-benzyloxy, as well as carbo-diphenylmethoxy or carbo-(u-4-bipheny1yl-u-methyl-ethoxy) groups. Carbolower alkoxy groups, in which the lower alkyl residue contains monocyclic monoazacyclic, monooxacyclic or monothiacyclic groups are, felt example, carb'o-furyllower alkoxy, such as carbo-furfuryloxy groups, or carbothienyl-lower alkoxy, for example, carbo-2-thenyloxy groups.

A lower alkanecarboxylic or lower alkenecarboxylic acid is, for example, acetic, propionic, butyric, isobutyric, valeric, pivalic or acrylic acid, while a cycloalkanecarboxylic or cycloalkenecarboxylic acid and a cycloalkylor cycloalkenyl-lower alkaneor -lower alkenecarboxylic acid, respectively, is, for example, a cyclopentanecarboxylic, cyclohexanecarboxylic or 3-cyclohexenecarboxylic acid, and a cyclopentylpropionic, cyclohexylacetic, 3-cyclohexenylacetic or hexahydrocinnamic acid, respectively.

A monocyclic or bicyclic aromatic carboxylic acid is, for example, benzoic acid or 1- or Z-naphthalenecarboxylic acid, and a phenyl-lower alkanecarboxylic or phenyl lower alkenecarboxylic acid, for example, a phenylacetic, phenylpropionic or cinnamic acid.

As heterocyclic carboxylic acids, nicotinic acid or isonicotinic acid, 2-thiophenecarboxylic, Z-furanecarboxylic, 2- or 4-quinolinecarboxylic or l-isoquinolinecarboxylic acid may be mentioned, and as corresponding lower alkanecarboxylic or lower alkenecarboxylic acids substituted by heterocyclic residues, for example, 2-, 3- or 4- pyridylacetic, Z-thienylacetic, 2-furylacetic or Z-furylacrylic acid may be mentioned.

The compounds of the present invention may be in the form of mixtures of isomers or in the form of pure isomers.

The compounds according to the invention represent novel intermediates which are suitable for the manufacture of valuable compounds which primarily exhibit pharmacological properties. Thus, it is, for example, possible, in compounds of Formula I, in which R denotes an organic, primarily an easily removable organic residue R of an alcohol, for example, an organic residue of an alcohol which can be removed by reduction, such as a 2-halogeno-lower alkyl, for example, the 2,2,2-trichloroethyl or the 2-iodoethyl residue, or an organic residue of an alcohol which can be removed under acid conditions, such as a methyl residue which is polysubstituted by optionally substituted aliphatic or aromatic hydrocarbon residues, for example, the benzhydryl, trityl, tert.- butyl or tert.-pentyl, as well as the adamantyl residue, R represents an acyl residue R preferably an acyl residue R which is easily removable, for example, under acid conditions, above all the acyl residue of a half-ester of carbonic acid, for example, the carbo-tert.-butyloxy, carbo-tert.-pentyloxy, carbo-vinyloxy, carbo-adamantyloxy 0r carbo-furfuryloxy, as well as carbo-diphenylmethoxy or carbo-(a-4-biphenylyl-u-methyl-ethoxy) residue, R and R have the above-mentioned significance and are primarily taken together and represent a carbon atom which is disubstituted, preferably by lower alkyl, especially methyl groups, to replace the hydroxyl group by a reactive esterified hydroxyl group, especially a halogen atom, for example, by treatment with suitable halogenating agents, for example, a thionyl halide, such as chloride, or a phosphorus oxyhalide, such as oxychloride, as well as a suitable sulfonic acid halide, such as chloride, preferably in the presence of a base, such as triethylamine, diisopropylethylamine or pyridine. From the resulting compounds of the formula in which X is a reactive esterified hydroxy group, especially a halogen, primarily a chlorine, as well as a bromine atom, and in which R is one of the above, for

example, an easily removable organic residue, by reaction 'with phosphine compounds of formula P(R,) (R (R wherein each of the residues R R and R represents an optionally substituted hydrocarbon residue, especially an optionally substituted aliphatic or aromatic hydrocarbon residue, for example, with triphenylphosphine or tributylphosphine, via the corresponding phosphonium salts, preferably by treatment with a basic reagent, one obtains the phosphorane compounds of the formula wherein RM and Rg preferably represent the abovementioned removable residues R and R28, respectively. These compounds represent starting substances of the Wittig-type which can be used for numerous purposes.

Compounds of the type of Formula B can, for example, be reacted with carboxaldehyde compounds of the formula wherein R represents a free or etherified hydroxyl group or a carbon atom which, in addition to at least one hydrogen atom, contains optionally substituted hydrocarbon residues, especially optionally substituted aromatics, as well as aliphatic hydrocarbon residues, such as phenyl groups, as well as lower alkyl group, or tautomers or reactive derivatives thereof, such as, for example, the hydrates or enols thereof, the reaction being preferably carried out at an elevated temperature, for example, at about 50 C. to about 150 C., and in an inert solvent, such as a hydrocarbon, for example, toluene or xylene, or in an ether, for example, dioxane 0r diethyleneglycol dimethyl ether, or a solvent mixture. Compounds of the formula wherein R, R R and R have the above-mentioned significance, especially the preferred significance, and in which R 4 stands for an easily removable (particularly under acidic conditions) acyl residue R are thus obtained.

In compounds of Formula D, in which R represents a free or etherified hydroxyl group, especially a lower alkoxy, for example, a methoxy, ethoxy, tert.-butyloxy or tert.-pentyloxy group, a halogeno-lower alkoxy, for example, 2,2,2-trichloroethoxy group, a cycloalkoxy, for example, adamantyloxy group, a phenyl-lower alkoxy, for example, benzhydryloxy group, or a furyl-lower alkoxy, for example, furfuryloxy group, the double bond can be saturated, for example, by treatment with catalytically activated hydrogen, for example, in the presence of a noble metal catalyst, such as a palladium catalyst, a chemical reducing agent, for example, by treatment with a suitable zinc compound, such as zinc, zinc amalgam or zinc-copper, e.g. in the presence of a reagent capable of furnishing hydrogen, such as a weak carboxylic acid, for example, acetic acid, or a lower alkanol, such as methanol, ethanol or isopropanol, if desired, an aqueous mixture thereof, or a homogenous hydrogenation catalyst, such as a transition metal hydride, for example, a corresponding chromium-III, manganese-II, iron-III, cobalt-II or nickel-II compound or a complex, such as a carbonyl, cyano or phosphine complex thereof.

On treatment with a strong, preferably oxygen-containing, inorganic or organic acid, primarily trifiuoroacetic acid, in the presence of an anhydride of a strong acid, for example, trifluoroacetic acid anhydride, if necessary, followed by an additional acid anhydride, especially acetic acid anhydride, a resulting compound of the formula wherein R, represents a hydrogen atom or one of the easily removable organic residues of an alcohol R mentioned for the group R and in which R stands for an easily removable (particularly under acidic conditions) acyl residue R can, optionally after removal of an easily removable acyl group R and/ or conversion of an intermediate of Formula -E, wherein R, represents a hydrogen atom into a reactive derivative, such as an acid halide, for example, acid chloride (using, for example, thionyl chloride or oxalyl chloride) or a mixed anhydride for example, with a carbonic acid lower alkyl half-ester such as ethyl half-ester (using, for example, a halogenoformic acid lower alkyl ester) or with a lower alkanecarboxylic acid, such as acetic acid (using, for example, a corresponding anhydride), be ring-closed, with splitting of the R -S-bond as well as of the R -N-bond to give a compound of the formula and, if desired, in a resulting compound a hydrogen atom R can optionally be replaced by an acyl group and/or an organic residue R; can optionally be replaced by hydrogen. Compounds of the type (B), primarily those in which R represents a hydrogen atom and R represents an acyl group, are antibiotically active against various micro-organisms, for example, against gram-positive and gram-negative bacteria, such as Staph. aureus, Proteus vulgaris and Bacillus megatherium and are useful accordingly.

Furthermore, compounds of the type of Formula D, in which R denotes an organic, especially an easily removable, for example, reductively removable organic residue of an alcohol R such as a Z-halogen-lower alkyl, for example, the 2,2,2-trichloroethyl residue, or an organic residue of an alcohol which can be removed under acid conditions, such as a methyl residue which is polysubstituted by optionally substituted aliphatic or aromatic hydrocarbon residues, for example, the benzhydryl, trityl, tert.-butyl, tert.pentyl or adamantyl residue, Rg represents an easily, for example, under acidic conditions removable acyl residue R such as the acyl residue of a half-ester of carbonic acid, removable, for example, under acid conditions, such as the carbo-tert.-butyloxy, carbotert.-pentyloxy, carbo-vinyloxy, carbo-adamantyloxy or carbo-furfuryloxy, as well as carbo-diphenylmethoxy or carbo (u-4-biphenylyl-a-methyl-ethoxy) residue, R and R have the above-mentioned significance and are primarily taken together to represent a carbon atom which is disubstituted, preferably by lower alkyl, especially methyl groups, and R represents a carbon atom which apart from at least one hydrogen atom contains optionally substituted hydrocarbon residues or also optionally substituted heterocyclic or heterocyclic-aliphatic residues, in which heterocyclic groups possess aromatic character, or contains functional groups, and especially represents a corresponding carbon atom which preferably contains as substituents one or two lower alkyl groups or a phenyl group optionally substituted as mentioned above, for example, by hydrocarbon residues, such as lower alkyl groups or by functional groups such as the etherified or esterified hydroxyl groups, for example, lower alkoxy groups or halogen atoms, or nitro groups, such a phenyl group optionally also together with a lower alkyl group, or an acyl group, for example, an optionally substituted benzoyl group, can be ring-closed by treatment with a suitable acid reagent, for example, trifluoroacetic acid. In resulting compounds of the formula wherein R represents a carbon atom which is substituted by optionally substituted hydrocarbon residues, optionally substituted heterocyclic or heterocyclic-aliphatic residues, wherein heterocyclic groups possess aromatic character, or functional groups, an organic group R can be replaced by hydrogen and/ or a hydrogen atom R and/ or R can be replaced by an organic group R and an acyl residue R especially by a suitable acyl residue, respectively.

Compounds of type (G), especially those in which R represents a hydrogen atom and R represents a suitable acyl residue of an organic carboxylic acid, especially an acyl residue occurring in pharmacologically active 6-acylamino-penicillanic acid derivatives or 7- acylaminocephalosporanic acid derivatives, show excellent antibiotic effects against various micro-organisms, especially grampositive bacteria, such as Staph. aureus and Proteus vulgaris and can be useful accordingly.

The invention primarily relates to compounds of the formula wherein R represents a hydrogen atom or a lower alkyl, such as a methyl or ethyl, especially a tert.-butyl, as well as tert.-pentyl residue, a halogeno-lower alkyl, primarily a 2-halogeno-lower alkyl, such as a 2,2,2 trichloroethyl residue, a cycloalkyl, for example, adamantyl residue, or a phenyl-lower alkyl, especially diphenylmethyl residue, particularly an easily removable organic residue of the above type, R represents a hydrogen atom or the residue R R represents an acyl residue, especially an acyl residue occurring in pharmacologically active N-acyl derivatives of 6-aminopenicillanic acid or 7-amino-cephalosporanic acid, such as a phenylacetyl, phenyloxyacetyl, phenylglycyl (optionally having a protected amino group), thienylacetyl, for example, 2-thienylacetyl, chloroethylcarbonyl or cyanoacetyl residue, or an easily removable acyl residue, especially the residue of a half-ester of carbonic acid, such as a carbo-lower alkoxy, for example, carbotert.-butyloxy or carbo-tert.-pentyloxy residue, a carbocycloalkoxy, for example, carboadamantyloxy residue, or

a carbo-furyl-lower alkoxy, for example, carbofurfuryloxy residue, as well as a carbo-diphenylmethoxy or carbo-(a-4- biphenylyl u methyl ethoxy) residue, each of the residues R and R represents a lower alkyl, especially a methyl residue, and R denotes the 2-propenyl or a 2-lower alkanoyloxy-Z-propyl, such as 2-acetoxy-2-propyl group.

Particularly valuable intermediates are the u-(Z-carbolower alkoxy 3,3 dimethyl 7 oxo 4 thia 2,6- diazo 6 bicyclo[3,2,0]heptyl) a hydroxy acetic acid lower alkyl esters, wherein the lower alkyl residue of the ester grouping may optionally possess one or more halogen atoms, preferably in 2-position, and primarily represents the tert.-butyl or 2,2,2 trichloroethyl residue, while the carbo-lower alkoxy residue in the 2-position preferably represents the carbo-tert.-butyloxy residue.

The compounds of the present invention can be obtained in a surprising manner, when a l-unsubstituted azetidin- 2-one compound of formula wnerein R represents an acyl residue, is reacted with a compound of formula O=CHCOOR (III) wherein R represents the organic residue of an alcohol, or with a reactive derivative thereof, and, if desired, the acyl group R is split off in a resulting compound, and, if desired, in a compound thus obtained the free nitrogen atom is acylated, and/or the resulting ester compound is converted to the corresponding free acid compound, and, if desired, a free carboxylic acid compound thus obtained is converted to an ester, and/or, if desired, a resulting compound having a salt-forming group is converted into a salt or a resulting salt into the free compound or into another salt, and/or, if desired, a resulting isomer mixture is resolved into the individual isomers.

The above reaction, that is to say the addition of the glyoxylic acid ester compound to the nitrogen atom of the lactam ring, preferably takes place at an elevated temperature, primarily at about 50 C. to about C. and, in particular, in the absence of a condensing reagent and/or without the formation of a salt, it being also possible to use, instead of the glyoxylic acid compound, a reactive oxo-derivative thereof. The latter is primarily a hydrate, with any resulting water, if necessary, being removed by distillation, for example, azeotropically.

The process is preferably carried out in the presence of a suitable solvent such as, for example, dioxane or toluene, or solvent mixture, if desired or required, in a closed vessel under pressure and/or in the atmosphere of an inert gas, such as nitrogen.

In a resulting compound an acyl group R especially an easily removable acyl residue, can be split off in a manner which is in itself known, a carbo-tert.-butyloxy group, for example, by treatment with trifluoroacetic acid, a carbo 2,2,2 trichloroethoxy group, for example, by treatment with a suitable metal or metal compound, for example, zinc or with a chromium-II compound, such as chromium-II chloride or acetate, preferably in the presence of a hydrogen-furnishing compound capable of producing nascent hydrogen together with the metal or metal compound, such as aqueous acetic acid.

In a compound obtained in this way the unsubstituted nitrogen atom in the 3-position can be acylated according to methods which are in themselves known, for example, by treatment with carboxylic or sulphonic acids or acid derivatives thereof, such as halides, for example, chlorides or anhydrides (whereby there are also to be understood the internal anhydrides of carboxylic acids, i.e. ketenes, or of carbamic or thiocarbamic acids, i.e. isocyanates or isothiocyanates) or activated esters, whereby suitable condensing reagents, such as carbodiimides, for

example, dicyclohexylcarbodiimide, may be used, if necessary.

In a resulting compound as ester grouping can be converted to the free carboxyl group; for example, a carbodiphenylmethoxy or carbo-tert.-butyloxy group can be converted by treatment with an acid reagent, such as trifluoroacetic acid. A carboxyl group esterified by a 2- halogeno-lower alkanol, especially 2,2,2-trichloroethanol, as well as 2-iodoethanol, can be converted to the free carboxyl group by treatment with chemical reducing agents, for example, by the action of treatment with reducing metals, metal alloys or metal amalgams, preferably in the presence of hydrogen-furnishing compounds capable of producing nascent hydrogen with the metals, metal alloys or metal amalgams, such as zinc, zinc alloys, for example, zinc-copper, or zinc amalgam, preferably in the presence of acids, which optionally contain water, such as organic carboxylic acids, for example, lower alkanecarboxylic acids, primarily acetic acid, or alcohols, such as lower alkanols, or alkali metal amalgams, e.g. sodium or potassium amalgam, or aluminium amalgam in the presence of a moist solvent, such as ether, and also by treatment with strongly reducing metal salts, such as chromium-II compounds, for example, chromium-II-chloride or chromium-II-acetate, preferably in the presence of an aqueous medium containing organic solvents miscible with water, such as lower alkanols, lower alkanecarboxylic acids or ethers, for example, methanol, ethanol, acetic acid, tetrahydrofuran,dioxane, ethylene glycol dimethyl ether or diethylene glycol dimethyl ether.

A resulting free carboxylic acid compound can be converted into its salts, such as, for example, alkali or alkaline earth metal or ammonium salts, or into its esters in a manner which is in itself known. Free carboxyl groups can, for example, be esterified by treatment with a diazo compound, such as a diazo-lower alkane, for example, diazomethane or diazoethane, or a phenyl-diazolower alkane, for example, phenyldiazomethane or diphenyldiazomethane, or by reaction with an alcohol suitable for esterification in the presence of an esterifying reagent, such as a carbodiimide, for example, dicyclohexylcarbodiimide, as well as carbonyldiimideazole, or according to any other known and suitable esterification procedure, such as reaction of a salt of the acid with a reactive ester of an alcohol and of a strong inorganic acid, as well as of a strong organic sulphonic acid. Furthermore, acid halides, such as acid chlorides (manufactured, for example, by treatment with oxalyl chloride), or activated esters, for example, esters with N-hydroxynitrogen compounds, or mixed anhydrides formed, for example, with halogenoformic acid lower alkyl esters, such as chloroformic acid ethyl esters, can be converted into the esters by reaction with alcohols, optionally in the presence of a base, such as pyridine.

Resulting mixtures of isomers can be resolved into the individual isomers according to methods which are in themselves known, for example, by fractional crystallization, adsorption chromatography (column or thin layer chromatography) or other suitable resolution processes. Resulting racemates can be resolved into the antipodes in the usual manner, for example, by forming a mixture of diastereoisomeric salts with optically active, saltforming reagents, resolving the mixture into the diastereoisomeric salts and converting the separated salts into the free compounds, or by fractional crystallization from optically active solvents.

The process also comprises those modifications, according to which compounds resulting as intermediates are used as starting substances and the remaining process stages are carried out With these, or according to which the process is stopped at any stage; furthermore, starting materials can be used in the form of derivatives or formed during the reaction Preferably those starting materials are used and those reaction conditions are chosen, which lead to the com- 12 pounds previously mentioned as being particularly preferred.

Starting materials used in accordance with the process, in which R and R together represent a disubstituted carbon atom, are known. Others, in which R denotes a removable organic residue and R stands for a hydrogen atom, can, for example, be obtained, when in a 6-N- acylamino-penicillanic acid compound the carboxyl group is converted into an isocyanato group in a manner which is in itself known, the compound thus obtained is treated with a 2-halogeno-lower alkanol, for example, 2,2,2-trichloroethano1 or 2-iodoethanol, and the substituent in the 2-position in a resulting 6-acylamino-2- (N-carbo 2-halogeno-lower alkoxy amino)-3,3-dirnethyl- 4-thia-l-azabicyclo[3,2,0]heptan-7-one compound is split by treatment with a chemical reducing agent, for example, zinc in the presence of strength acetic acid. The resulting 6-acylamino-2-hydroxy-3,3-dimethyl-4-thial-azabicyclo[3,20]heptan-7-one compound is treated with a heavy metal acylate oxidizing reagent, especially a lead- IV-carboxylate, such as a lead-IV-lower alkanoate, for example, lead tetraacetate, usually with irradiation, preferbly with ultraviolet light, can be converted to a 3- acylamino 2 (Z-acyloxy-2-propylmercapto)-l-formylazetidin-4-one compound. If desired, the acyloxy group together with hydrogen can be split off in the form of the corresponding acid by heating, and with formation of the 2-propenylrnercapto grouping. The formyl group attached to the ring nitrogen atom can be removed by treatment with a suitable decarbonylation agent, such as a tris-(tri-organically substituted phosphine)-rhodium halide, for example, tris-(triphenylphosphine)-rhodium chloride, in a suitable solvent, e.g. benzene, as well as by hydrolysis, for example, with an aqueous alkali metalhydroxide, or by ammonolysis with aqueous ammonia in the presence of an organic solvent, which is only slightly miscible with water, or with conversion of the formyl group into the carbinol group, for example, by treatment with catalytically activated hydrogen in the presence of an acid reagent, such as with hydrogen in the presence of a palladium catalyst and glacial acetic acid or tetrahydrofuran containing hydrochloric acid. If desired, the 2-acyloxy-2-propyl residue of a resulting compound can be replaced by another organic residue by treatment with a weakly basic reagent, such as an alkali metal hydrogen carbonate or pyridine, in the presence of a reactive ester of an alcohol, such as a suitable halide.

The present invention also includes the compounds of the Formula A (manufactured from those of the Formula I), in which R R R and R have the previously given meaning, and in which a reactive esterified hydroxyl group is primarily a halogen, such as a chlorine or bromine atom, as well as an organic, for example, aliphatic or aromatic, sulfonyloxy group, such as a lower alkyl, e.g. methylor ethylsulfonyloxy group, or an aryl, e.g. phenyl-, 4-methylphenyl-, 4-bromopheny1- or 3-nitr0- phenylsulfonyloxy group. These are primarily the compounds of he formulae R 3 (Ab) in which R represents one of the organic residues R R R R and R have the previously given meaning and Hal stands for a chlorine or bromine atom. Especially mentioned are the u-(2-carbo-lower alkoxy-3,3-dimethyl 7 oxo 4 thia 2,6 diaza-6-bicyclo[3,2,0] heptyl)-a-Hal acetic acid lower alkyl esters, in which Hal has the above given meaning, and the lower alkyl residue of the ester grouping optionally possesses one or more halogen atoms, preferably in the 2-position, and primarily represents the tert.-butyl or 2,2,2-trichloroethyl residue, while the carbo-lower alkoxy residue in the 2-position preferably represents the carbo-tert.-butyloxy residue.

The compounds of the Formula A can be obtained, when in an a-hydroxy-2-oxo-1-azetidine-methanecarboxylic acid ester of the Formula I, wherein R represents the organic residue of an alcohol and R represents an acyl group R the hydroxyl group is converted to a reactive esteri-fied hydroxyl group by treatment with an esterifying acid derivative, and, if desired, in a resulting compound, a reactive esterified hydroxyl group is converted into another reactive esterified hydroxyl group, and/or, if desired, a resulting compound having a saltforming group is converted to a salt or a resulting salt is converted to the free compound or to another salt and/ or, if desired, a resulting isomer mixture is resolved into the individual isomers.

The above reaction is carried out by treating the starting material with a suitable halogenating agent, such as a thionyl halide, for example, thionyl chloride, a phosphorus oxyhalide, especially phosphorus oxychloride, or a halogenophosphonium halide, such as triphenylphosphine dibromide or diiodide, as well as by treatment with a suitable organic sulphonic acid halide, such as chloride, preferably in the presence of a basic reagent, primarily of an organic basic reagent, such as an aliphatic tertiary amine, for example, triethylamine or diisopropylethylamine, or a heterocyclic base of the pyidine type, for example, pyridine or collidine.

The process is preferably carried out in the presence of a suitable solvent, for example, dioxane or tetrahydrofuran, or of a solvent mixture, if necessary, while cooling and/or in the atmosphere of an inert gases, such as nitrogen.

In a resulting compound, a reactive esterified hydroxyl group X can be converted into another reactive hydroxyl group in a manner which is in itself known. Thus, for example, a chlorine atom can be replaced by a bromine or iodine atom by treating the corresponding chlorine compound with a suitable bromine or iodine compound, especially with an inorganic bromide or iodide salt, such as lithium bromide, preferably in the presence of a suitable solvent, such as ether.

Also included within the scope of the present invention are compounds of the Formula B, in which R R R and R have the previously given meaning, and each of the groups R,,, R and R represents an optionally substituted hydrocarbon residue, primarily an optionally substituted aliphatic or aromatic, as well as also an optionally substituted cycloaliphatic, cycloaliphatic-aliphatic or araliphatic hydrocarbon residue. These compounds are especially those of the formulae C O OR in which R R R R and R have the previously given meaning, and each of the groups R,. R and R represents a lower alkyl residue, which is optionally substituted, for example, by etherified or esterified hydroxyl groups, such as lower alkoxy groups or halogen atoms, or a phenyl residue which is optionally substituted as mentioned above, for example, by aliphatic hydrocarbon residues, such as lower alkyl groups, or etheri-fied or esterified hydroxyl groups, such as lower alkoxy groups or halogen atoms, or nitro groups. Particularly valuable are the a-(tri-R -phosphoranylidene) a (Z-carbo-lower alkoxy 3,3-dimethyl-7-oxo-4-thia-2,6-diaza-6-bicyclo[3,2,0] heptyl)-acetic acid lower alkyl esters, in which the lower alkyl residue of the ester grouping optionally possesses one or more halogen atoms, preferably in the 2-position, and which primarily represents the tert.-butyl or 2,2,2- trichloroethyl residue, while the carbo-lower alkoxy residue in the 2-position preferably represents the carbo-tert.- butyloxy residue, and R stands for a lower alkyl group or the phenyl group.

The compounds of the Formula B can be obtained, when a reactive ester of an a-hydroxy-2-oxo-l-azetidinemethanecarboxylic acid ester of Formula A is reacted with a phosphine compound of the formula R.I Rs

and, if necessary, a phosphonium salt compound obtainable as an intermediate product is converted to the corresponding phosphorane compound with the elements of the acid H-X being split off and, if desired, a resulting isomer mixture is resolved into the individual isomers.

In the starting material of Formula A, a group X primarily represents a halogen, especially a chlorine or bromine, as well as an iodine atom; X can also represent an organic, primarily an aliphatic or aromatic, sulphonyloxy group, for example, an optionally substituted lower alkylsulphonyloxy, e.g. methylsulphonyloxy, ethylsulphonyloxy or Z-hydroxy-ethylsulphonyloxy group, or an optionally substituted phenylsulphonyloxy group, for example, 4-methylphenylsulphonyloxy, 4-bromophenylsulphonyloxy or 3-nitrophenylsulphonyloxy group. In the phosphine compound of Formula IV, the residues R R and R have the above-mentioned significance and primarily represent optionally substituted lower alkyl or phenyl residues, for example, n-butyl or phenyl groups.

The above reaction is preferably performed in the presence of a suitable inert solvent, such as an aliphatic, cycloaliphatic or aromatic hydrocarbon, such as hexane, cyclohexane, benzene or toluene, or of an ether, such as dioxane, tetrahydrofuran or diethylene glycol dimethyl ether, or a solvent mixture. If necessary, the process is carried out while cooling or heating and/ or in the atmosphere of an inert gas such as nitrogen.

Usually, a phosphonium salt compound of the formula RI 0=C--N/ 81 R,

H- H R. Xe R;AN/ s formed as an intermediate loses the elements of the acid H-X spontaneously; if necessary, the phosphonium salt compound can be decomposed by treatment with a weak base, such as an organic base, for example, diisopropylethylamine or pyridine.

The invention is described in more detail in the examples below. Temperatures are given in degrees centigrade.

EXAMPLE 1 A solution of 3 g. of 2-carbo-tert.-butyloxy-3,3-dimethyl-4-thia-2,6-diaza-bicyclo[3,2,0]heptan-7-one in 23.3 ml. of dry dioxane is mixed with 5.2 g. of glyoxylic acid 2,2,2-trichloroethyl ester hydrate; the reaction vessel is closed and heated for 7 hours at 95 bath temperature. The slightly yellowish, clear reaction solution is diluted with 150 ml. of benzene and washed three times with 150 ml. of water at a time, in the course of which resulting emulsions can be broken in a simple manner by adding 20 ml. of a concentrated aqueous solution of sodium chloride. The combined aqueous solutions are washed with 150 ml. of benzene; the combined organic solutions are dried with sodium sulphate and evaporated under reduced pressure. The viscous residue is dissolved in 60 ml. of a 3:1mixture of pentane and ether, whereupon the higher-melting isomer of the a-(Z-carbo-terL- butyloxy-3,3-dimethyl 7 oxo-4-thia-2,6-diaza-6-bicyclo [3,2,0]heptyl)-a-hydroxy-acetic acid 2,2,2-trichloroethyl ester of the formula crystallizes in prisms, which are filtered off when needleshaped crystals begin to appear, M.P. 14l146; analytical sample: M.P. 146-147; [a] =--307:l (c.=0.938 in chloroform); infrared absorption spectrum (in methylene chloride): characteristic bands at 2.7,u, 5.6,u, 5.68;, 5.85% 7.32 L, 8.65,:1. and 9.411..

The clear filtrate is evaporated and the residue is recrystallized from 50 ml. of 5:l-mixture of pentane and ether, whereupon the lower-melting isomer of the a-(2- carbo-terL-butyloxy-S,3-dimethyl 7 oxo 4 thia-2,6- diaza--bicyclo[3,2,0]heptyl)-a-hydroxy-acetic acid 2,2,2- trichloroethyl ester is obtained which melts in colorless needles at 125-129; analytical sample: M.P. 126-129"; [a] =187i2 (c.=0.625 in chloroform); infrared adsorption spectrum (in methylene chloride); characteristic bands at 2.8 2, 5.6 5.84 7.3 1. and 7.36;.

After 2 days, additional crystalline material is obtained from the mother liquor and after recrystallization from a 3: l-mixture of pentane and ether, this material, in the form of prisms, melts at 140-145 and is identical with the higher boiling isomer. A further quantity of the needleshaped lower-melting isomer, M.P. 127-131, is obtained from the filtrate.

EXAMPLE 2 A mixture of 5 g. of 2-carbo-tert.-butyloxy-3,3-dimethyl-4-thia-2,6-diaza-bicyclo[3,2,0]heptan-7-one and 5.5 g. of glyoxylic acid tert.-butyl ester hydrate in 40 ml. of dioxane is stirred for 13 /2 hours at 95 in a closed vessel and then evaporated. The residue is dissolved in 1000 ml. of pentane, Washed three times with 500 ml. of water and once with 200 ml. of a saturated aqueous sodium chloride solution, dried over dry sodium sulphate and evaporated. An approximately 50:50-mixture of the two isomers of a-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo-4- 16 thia-2,6-diaza 6 bicyclo[3,2,0]heptyl)-a-hydroxy-acetic acid tert.-butyl ester of the formula is thus obtained. 0.9 g. of the resulting mixture is crystallized from pentane and recrystallized from a mixture of ether and pentane, whereupon one isomer of the above compound, M.P. 134l37, is obtained; [a] =365i1 (c.=1.l02 in chloroform); thin layer chromatogram:

R =0.49 in a lzl-mixture of benzene and ethyl acetate; infrared absorption spectrum (in methylene chloride): characteristic bands at 2.94,:r, 5.62,u, 5.77 1. and 5.85;.

EXAMPLE3 is obtained; M.P. 125-127; infrared absorption spectrum with characteristic HO-band at 2.7;/..

EXAMPLE 4 A solution of 0.05 g. of the higher-melting isomer of a-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo 4 thia-2,6- diaza-6bicyclo[3,2,0]heptyl)-a-hydroxy-acetic acid 2,2,2- trichloroethyl ester (Example 1) in 3 ml. of distilled trifluoroacetic acid is stirred for 5 minutes and then evaporated under reduced pressure without warming. The residue is neutralized with a saturated aqueous sodium hydrogen carbonate solution and is extracted with 20 ml. of methylene chloride. The organic extract is dried and evaporated; the residue is recrystallized from a mixture of methylene chloride, ether and hexane; the resulting isomer of u-(3,3-dimethyl-7-oxo-4-thia-2,6-diaza 6 bicyclo [3,2,0]heptyl)-u-hydroxy-acetic acid 2,2,2-trichloroethy1 ester melts at 107109; analytical sample: M.P. 108- 110; [a] =--176i2 (m /20.513 in chloroform); infrared absorption spectrum (in methylene chloride): characteristic bands at 2.87 3.02,u, 5.68,!L, 7.33 and 9.08;.

EXAMPLE 5 A solution of 0.25 g. of glyoxylic acid tert.-butyl ester hydrate in 5 ml. of toluene is concentrated under normal pressure to a volume of about 3 ml. After cooling to 0.069 g. of 2a-isopropylmercapto-3a-N-phenyloxyacetylamino-azetidinl-one is added and after 2 hours the mixture is diluted with 20 ml. of benzene and washed three times with 20 ml. of water at a time; the aqueous washing solutions are back-washed with 10 ml. of benzene, and the combined benzene solutions are dried and evaporated. The residue is degassed at a pressure of 0.05 mm. Hg.;

@w-om-g-frn 949m).

still contains a small quantity of the glyoxylic acid tert.- butyl ester hydrate; infrared absorption spectrum (in methylene chloride): characteristic bands at 2.83,!L, 2.98 t, 3.05 t, 5.65 1 5.78 t, 5.93m, 6.26 t, 6.60 t, 6.7l L, 7.31.].L, 8.65/L and 9.23 4

The starting material used above can be manufactured as follows:

A solution of 2.625 g. of penicillin-V in 30 ml. of tetrahydrofuran is mixed with 5.31 ml. of a 10 mL-solution of 2 m1. of triethylamine in tetrahyrofuran while stirring and cooling to 10. 3.6 ml. of a 10 ml. solution of 2 ml. of chloroformic acid ethyl ester in tetrahydrofuran are then slowly added at -10 and, after completion of the addition, the mixture is stirred for 90 minutes at 10 to 5.

The reaction mixture is treated with a solution of 0.51 g. of sodium azide in 5.1 m1. of water, stirred for 30 minutes at to and diluted with 150 ml. of ice water. The mixture is extracted three times with methylene chloride; the organic extracts are washed with water, dried and evaporated at and under reduced pressure. The amorphous penicillin-V azide is thus obtained as a light yellowish oil; infrared absorption spectrum (in methylene chloride): characteristic bands at 3.04 t, 4.70M, 5.61M, 5.82 t (shoulder), 5.93/L, 6.26 t, 6.61 t, 6.71 t, 8.50 and 9.40 1" A solution of 2.468 g. of pencillin-V azide in ml. of benzene is heated for 30 minutes to The pure 2 isocyanato-3,3-dimethyl-6-(N-phenyloxyacetylamino)- 4-thia-1-azabicyclo[3,2,0]heptan-7 one can be obtained by evaporating the solution under reduced pressure; infrared absorption spectrum (in methylene chloride): characeteristic bands at 3.03 t, 4.46 u, 5.59 t, 5.93 4, 6.26 6.62 6.70 t, 7.53 8.28 t, 8.53 t, 9.24 t and 9.40 4.

The above solution of the 2-isocyanato-3,B-dimethyl- 6-(N-phenyloxyacetyl-amino) 4 thia-azabicyclo[3,2,0] heptan-7-one is mixed with 3.4 ml. of a 10 ml. solution of 2 ml. of 2,2,2-trichloroethanol in benzene and the reaction mixture is kept for minutes at 70. The solvent is removed under reduced pressure and the residue is purified on 40 ml. of acid-washed silica gel (column). Byproducts are eluted with 300 ml. of benzene and 300 ml. of a 19:1-mixture of benzene and ethyl acetate, and the pure 2-(N-carbo-2,2,2-trichloroethoxy-amino)-3,3-dimethyl-6-(N-phenyloxyacetyl-amino)-4-thia 1 azabicyclo [3,2,0]heptan-7-one of the formula NH-C O 0 01120 C13 is eluted with 960 ml. of a 9:1-mixture of benzene and ethyl acetate. After recrystallization from a mixture of ether and pentane, the product melts at 169-171 (with O decomposition); [a] =-l83 (c.=l.015 in chloroform); thin layer chromatogram (silica gel): Rf=0.5 in a lzl-mixture of benzene and ethyl acetate; infrared absorption spectrum (in methylene chloride): characteristic bands at 3.05 i, 5.62 t, 5.77/L, 5.93 i, 6.27/L, 6.62 4, 6.70 1,

830 9.23, and 9.50 t.

The last fractions eluted with a 9: l-mixture of benzene and ethyl acetate contain a small quantity of the product which is isomeric in the 2-position with the above compound.

A solution of 3 g. of crystalline 2-(N-carbo-2,2,2-trichloroethoxy-amino)-3,3 dimethyl-6-(N-phenyloxyacetylamino)-4-thia-1-azabicyclo[3,20 heptane-7-one in 65 ml. of 90% aqueous acetic acid and 30 ml. of dimethylformamide is mixed over the course of 20 minutes with 32.6 g. of Zinc dust while cooling with ice and then stirred for 20 minutes. The excess zinc is filtered off and the filtered residue is washed with benzene; the filtrate is diluted with 450 ml. of benzene, washed with a saturated aqueous sodium chloride solution and water, dried and evaporated under reduced pressure. The residue is purified on a column of 45 g. of acid-washed silica gel. A- polar products are eluted with ml. of benzene and 400 ml. of a 9:1-mixture of benzene and ethyl acetate and starting material with 100 ml. of a 4:1-mixture of benzene and ethyl acetate. Using a further 500 ml. of the 4: l-mixture of benzene and ethyl acetate and 200 ml. of a 2:1-mixture of benzene and ethyl acetate, the 3,3-dimethyl 2 hydroxy 6 (N-phenyloxyacetyl-amino)- 4-thia-1-aza-bicyclo[3,2,0]heptan-7-one of the formula is obtained; it crystallizes spontaneously as the hydrate and after trituration with water-saturated ether melts in an unsharp manner in the range of 62-85 When chromatographed, but noncrystalline starting material is used and the reduction is carried out in dilute acetic acid without the addition of dimethylformamide, the pure product, M.P. 62-70, is obtained; thin layer chromatogram (silica gel): Rf= 0.35 in a lzl-mixture of benzene and ethyl acetate; infrared absorption spectrum (in methylene chloride): characteristic bands at 2.93 t, 3.09 5.56;.1, 5.96 4, 62911., 6.65 t, 6.75 t, 8.57 t, 9.27 t, 10.0011 and 11.95

A solution of 0.065 g. of 3,3-dimethyl-2-hydroxy-6-(N phenyloxyacetyl-amino -4-thia-1-azabicyclo [3 ,2,0] heptan- 7-one in 5 ml. of benzene is treated with 0.15 g. of lead tetraacetate, containing 10% of acetic acid, and the yellow solution is irradiated with a high pressure mercury vapor lamp (80 watts) in a water-cooling pyrex glass jacket. After 10 minutes the yellow color disappears and a partially fiocculant white, partially gum-like yellow, precipitate forms. The mixture is diluted with benzene, Washed with water, a dilute sodium hydrogen carbonate solution and water, and evaporated under reduced pressure. The resulting 1-formyl-2-(2-acetyloxy-2-propylmercapto)-3-('N-phenyloxyacetyl-amino)azetidin-4-one of the formula til-5H om G-Q-Cm-C-N'n "s-o-o-o-cn.

ii on.

is obtained as a slightly yellowish gum-like product; infrared absorption spectrum (in methylene chloride); characteristic'bands at 3.05 t, 5.56 2, 5.78 t, 5.90/L, 6.27 4, 6.62/L, 6.7l 7.33 9, 7.67 t, 8.92 4, 9.'24 1., and 9.82 4.

A solution of 0.051 g. of 1-formyl-2-(2-acetyloxy-2- propyl mercapto) 3 (N phenyloxyacetyl amino)- azetidin-4-one in 3 ml. of anhydrous benzene is treated with 0.13 g. of tris-triphenyl-phosphine-rhodium chloride and boiled for 3 hours under reflux. The initially red solution turns brown, with a small quantity of a precipitate forming. After cooling, the precipitate is [filtered 0E and the filtrate is evaporated under reduced pressure.

19 The residue is chromatographed on g. of acid-washed silica gel, with fractions of 5 ml. each being collected. The elution is carried out with ml. of benzene, 30' ml. of a 9:1-, 25 ml. of a 4:1- and 10 ml. of a lzl-mixture of benzene and ethyl acetate and then with 25 ml. of ethyl acetate. Fractions 2-6 yield a rhodium complex having a strong CO-absorption at 5.18 4 in the infrared absorption spectrum. A small quantity of 1-formyl-2-isopropenylmercapto-B-(N-phenyloxyacetyl amino) acetidin-4 one can be isolated from fractions 10-12, while fractions 17 yield the 2-isopropenylmercapto 3 (N-phenyloxyacetyl-amino)-azetidin-4-one of the formula in an amorphous form. The product is obtained in crystalline form when the solution of the eluate is filtered through 0.5 g. of acid-washed silica gel and the product is eluted with a lzl-mixture of benzene and ethyl acetate, M.P. 156158 [a] ='-70:t2 (c -0.665 in chloroform); infrared absorption spectrum (in methylene chloride): characteristic bands at 3.07 5.65 5.96,:4, 6.29 6.59,u, 6.74 8.19p., 925 and 9.92

A solution of 0.08 g. of 2u-isopropenylmercapto-3-(N- phenyloxyacetyl-amino)-azetidin-4-one in 10 ml. of ethyl acetate is mixed with 0.1 g. of a 10% palladium-on-charcoal catalyst and the mixture is stirred for 45 minutes in a hydrogen atmosphere and then filtered. The filtrate is evaporated and [the crystalline residue is recrystallized from a mixture of methylene chloride and ether. The isopropylmercapto 3 (N phenyloxyacetyl amino)- azetidin 4 one of the formula is thus obtained, M.P. 128130 and 143 (double melting point); [oc] =48i1 (c. =0.785 in ch1oroform); infrared absorption spectrum (in methylene chloride): characteristic bands at 3.05,u., 5.63 4, 5.93 6.26 4, 6.58 6.70;, 8.15,u, 9.21 and 9.4114.

EXAMPLE '6 By concentrating a solution of 0.414 g. of glyoxylic acid tert.-butyl ester hydrate in 5 ml. of toluene to a volume of 3 ml. the anhydrous compound is obtained; the solution is treated at 90 With 0.128 g. 2a-isopropenylmercapto-3a-(N-phenyloxyacetyl amino)-azetidin- 4-one. The mixture is 'kept at 90 for three hours and after cooling is treated with methylene chloride, washed with water, dried and evaporated under reduced pressure. The residue is chromatographed on 10 g. of acid-washed silica gel. The amorphous mixture of the two isomers of a-hYdl'OXY-ot-[Zoc isopropenylmercapto 4 oxo3u-(N- phenyloxyacetyl-amino) 1 azetidinyl]acetic acid tert.- butyl ester of the formula is eluted with a 4: l-mixture of benzene and ethyl acetate, infrared absorption spectrum (in methylene chloride): characteristic bands at 2.95,u., 3.03,u, 5.62 5.78,u, 5.91 614a, 6.60, 6.70;/., 7.25,u, 8.62 1. and 9.22,u.

The compounds which can be manufactured according to the above process can be further processed as follows:

20 EXAMPLE 7 A soution of 1.84 g. of the higher-melting isomer of ot-(2-carbo-terL-butyloxy 3,3 dimethy1-7-ox0-4-thia-2,6- diaza-6 bicyclo[3,2,0]he tyD-a-hydroXy-acetic acid 2,2,2- trichloroethyl ester in'20 ml. of a 1:4-mixture of dry dioxane and tetrahydrofuran is mixed with 12 ml. of freshly prepared 1 molar solution of triethylamine in dioxane. The mixture is cooled to l5 and treated dropwise with 8 ml. of a freshly prepared 1 molar solution of thionyl chloride in dioxane, with exclusion of atmospheric moisture, and is then stirred for 5 minutes at -15. After warming to room temperature and 10' minutes stirring at 20, the mixture is diluted with 60 ml. of toluene and filtered through a glass filter. The clear filtrate is evaporated under reduced pressure and at a bath temperature of below 45. The residue is dried for 2 hours at 25 0.1 mm. Hg. and is then triturated three times with 60 ml. at a time of boiling pentane; the solution is stirred for 10 minutes with 0.3 g. of an active charcoal preparation and is filtered through a glass filter. After evaporation, the residue is crystallized from pentane; the resulting a-(2-carbo-tert.-butyloxy-3,3-dimethyl- 7-oxo-4-thia 2,6 diaza '6 bicyclo[3,2,0-]heptyl)-achloroacetic acid 2,2,2-trichloroethyl ester of the formula melts at 131-136" after repeated recrystallizations from pentane; analytical sample: M.P. 130-431";

(c.=0.991 in chloroform); thin layer chromatogram (silica gel): Rf=0.73 (streaking) in kl-mixture of benzene and ethylacetate; infrared absorption spectrum (in methylene chloride): characteristic bands at 5.60;, 5.64 and 5.85 1.

EXAMPLE 8 A mixture of 12 g. of the so-called polystyrene- Hiinig base manufactured by warming a mixture of g. of chloromethylpolystyrene [J. Am. Chem. Soc. 85, 2149 (1963)], 500 ml. of benzene, 200 m1. of methanol and 100 ml. of diisopropylamine to 150 while shaking, filtering, washing with 1000 ml. of methanol, 1000 ml. of a 3:1-mixture of dioxane and triethylamine, 1000 ml. of methanol, 1000 ml. of dioxane and 1000 ml. of methanol and drying for 16 hours at 100/ 10 mm. Hg; the product neutralizes 1.55 milliequivalents of hydrochloric acid per gram in a 2: l-mixture of dioxane and water) in 50 ml. of a 1:1-mixture of dioxane and tetrahydrofuran is stirred for 30 minutes, and is then treated with a solution of 1.84 g. of the higher-melting isomer of a-(2-carbo-tert.-butyloxy-3,S-dimethyl 7 oxo 4- thia 2,6 diaza-6-bicyclo [3,2,0]heptyD-a-hydrOXy-acetic acid 2,2,2-trichloroethyl ester in 5 ml. of a lzl-mixture 0f dioxane and tetrahydrofuran. After cooling the mixture to 15 while stirring, 8 ml. of a freshly prepared 1 molar solution of thionyl chloride in dioxane are added dropwise; the mixture is stirred for 10 minutes at 15 and then for 90 minutes at 25. After filtering, the filter residue is washed three times with 30 ml. of dioxane at a time; the combined filtrates are evaporated at a bath temperature below 45. The a-(2-carbo-terhrbutyloxy- 3,3 dimethyl 7 oxo-4-thia-2,-6-diaza-6-bicyclo[3,2,0] heptyl)a-chloro acetic acid 2,2,2-trichloroethyl ester is obtained as a viscous residue, which, after recrystallization from 30 ml. of pentane, melts at 131.

EXAMPLE 9 A mixture of 6 g. of a 1:1-mixture of the isomers of oz (2 carbo. tert.-butyloxy-3,3-dimethy1-7-oxo-4-thia- 2,6 diaza 6 bicyclo[3,2,0]heptyl) a hydroxyacetic acid tert.-butyl ester and 10.5 g. of the so-called polystyrene-Hiinig base (see Example '8) in a 1:1- mixture of dioxane and tetrahydrofuran is stirred for 20 minutes. After cooling, the mixture is treated dropwise over the course of 20 minutes with a solution of 6 g. of thionyl chloride in 50 ml. of dioxane and is stirred for 140 minutes at 20 and then filtered. The filtrate is evaporated, the residue is taken up in 200 ml. of pentane and the solution is treated with 1 g. of an active charcoal preparation and then filtered. An approximately 1:1- mixture of the isomers of a-(2-carbo-tert.-butyloxy-3,3- dimethyl 7 oxo 4 thia 2,6diaza-6-bicyclo[3,2,0] heptyl)-a-chloro-acetic acid tert.-butyl ester of the formula is thus obtained and used without purification.

EXAMPLE 10 A solution of 0.165 g. of m-(2-carbo-tert.-butyloxy-3,3- dimethyl 7 oxo 4 thia 2,6-diaza-6-bicyclo'[3,2,0] he tyD-u-chIoro-acetic acid 2,2,2-trichloroethyl ester in 30 ml. of dry ether is mixed with 0.22 g. of dry lithium bromide and the suspension is stirred for 150 minutes at 25 The filtered solution is diluted with 20 ml. of pentane and then again filtered and evaporated. The residue is triturated with 20 ml. of 9:1-mixture of boiling pentane and ether and filtered and the clear filtrate is evaporated. The resulting oz (2 carbo tert. butyloxy 3,3- dimethyl 7 OX 4 thia 2,6-diazo-6-bicyclo[3,2,0] he tyD-m-bromQ-acetic acid 2,2,2-trichloroethyl ester of the formula melts at 119-120 (with decomposition) after crystallization from pentane.

EXAMPLE 11 A solution of 0.115 g. of the crude mixture of the isomers of u-hydroxy-a-(2a-isopropylmercapto-4-oxo-3a- N-phenyloxyacetylamino-1-azetidinyl)-acetic acid tert.- butyl ester (about 0.1 g. of the two epimers) in 2.4 ml. of anhydrous dioxane is mixed with 0.1 g. of polystyrene-Hiinig base and cooled to 0 while stirring. 0.06 g. of thionyl chloride in 0.5 ml. of dioxane are added and the mixture is stirred for a further 2% hours at room temperature and filtered; the filter residue is washed with dioxane and the filtrate is evaporated under reduced pressure. The residue contains the mixture of the isomers of the a chloro a (2a-isopropylmercapto-4-oxo-3a-N- phenyloxyacetylamino-1-azetidinyl)-acetic acid tert.-butyl ester of the formula O=CN "s-cmonm which shows the following characteristic bands in the infrared absorption spectrum (in methylene chloride): 3.05;, 5.63 5.75 5.93,u, 6.25;, 6.70 7.30 and 8.70

EXAMPLE 12 A solution of 11.3 g. of a crude mixture of the isomers of' u-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo-4- thia-2,6-diaza-6-bicyclo[3,2,0]heptyl) -u-ChlOI'O-3.C6ti0 acid tert.-butyl ester in 150 ml. of absolute dioxane is mixed with 11.4 g. of triphenylphosphine and 10.8 g. of polystyrene-Hiinig base or diisopropylaminomethyl-polystyrene, stirred for 17 hours at 55 under a nitrogen atmosphere and then cooled and filtered through a glass filter. The filter residue is washed with ml. of benzene, and the filtrate is evaporated under water jet pump vacuum; the residue is dried under a high vacuum; dissolved in 100 ml. of a 9zl-mixture of hexane and ethyl acetate and chromatographed on a column (height 4 8 cm.; diameter 6 cm.) of acid-washed silica gel. Triphenylphosphine and a small amount of triphenylphosphinesulphide are eluted with 2000 ml. of a 3:1-mixture of hexane and ethyl acetate, and the a-(2-carbo-terL-butyloxy 3,3 dirnethyl 7 oxo 4 thia-2,6-diaza-6-bicyclo [3,2,0]heptyl) a (triphenylphosphoranylidene) acetic acid tert.-butyl ester of the formula is eluted with an additional 4000 ml. of the 3:1 mixture of hexane and ethyl acetate; a further quanity of the impure product can be obtained with 1500 ml. of the same solvent mixture. The product has an Rf-value of 0.5 in a thin layer chromatogram (silica gel; system: 1:1-mixture of benzene and ethyl acetate) and crystallizes from a mixture of ether and pentane, M.P. 121-122";

'(c.=1.145 in chloroform); ultra-violet absorption spectrum '(in ethanol): A =225 m L (e=30,000) and 260 m (e=5400); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.76,u, 5.80;; (shoul der), 5.97;, 6.05.11. (shoulder) and 6.17;. A further quantity of the product can be isolated from the mother liquor by crystallization in an ether-pentane mixture.

EXAMPLE 13 A solution of 0.1 g. of u-(2-carbo-tert.-butyloxy-3,3- dimethyl 7-oxo-4-thia-2,6-diaza-6-bicyclo[3,2,0]heptyl)- a-chloroacetic acid 2,2,2-trichloroethyl ester in 3 ml. of dry benzene (after treatment with sodium and filtration through aluminium oxide, neutral, activity I) is treated with 0.072 g. of freshly distilled tri-n-butyl-phosphine and the mixture is stirred for 25 hours at room temperature. The resulting product is chromatographed on silica gel, whereupon the w(2-carbo-tert.-butyloxy-3,3-dimethyl-7- oxo 4 thia 2,6-diaza-6-bicyclo[3,2,0]heptyl)-u-(tri-nbutyl-phosphoranylidene)-acetic acid 2,2,2-trichloroethyl ester of the formula is obtained by means of a 9:1-mixture of benzene and ethyl acetate and used without further purification.

EXAMPLE 14 A mixture of 0.735 g. of polystyrene-Hiinig base in ml. of dioxane (treated with neutral aluminium oxide, activity I) is reacted with 0.34 g. of triphenylphosphine (recrystallized from hexane) and then with 0.5 g. of a-(Z carbo tert. butoxy-3,3dimethyl-7-oxo-4-thia-2,6- diaza-6-bicyclo[3,2,0]heptyl)-a-chlor0acetic acid 2,2,2- trichloroethyl ester and is stirred for 17 hours at 60 under a nitrogen atmosphere. The mixture is filtered through a glass filter and the filter residue is twice washed with 5 ml. of methylene chloride at a time and once with 5 ml. of benzene. The filtrate is evaporated to dryness under reduced pressure and the residue is chromatographed on silica gel. Triphenylphosphine, starting material and dehalogenated starting material are eluted with benzene and with a 19:1-mixture of benzene and ethyl acetate. The desired a-(2-carbo-tert.-butyloxy-3,3-dimethyl 7 oxo 4 -thia-2,6-diaza-6-bicyclo[3,2,0]heptyl)-a- (triphenylphosphoranylidene)-acetic acid 2,2,2-trichloroethyl ester of the formula COOCHzCCla O=(:J-II P( eHt)a on. CH-CH mo- O-CN s CH: C

H30 on;

is obtained with a 9:1-mixture of benzene and ethyl acetate, in an oily form; after two crystallizations from a methylene chloride-pentane mixture, the material melts at 205; [a] l92il (c.=1.054 in chloroform); thin layer chrom'atogram (silica gel): Rf-0.54 in the system benzene-ethyl acetate (3:1); ultraviolet absorption spectrum (in ethanol): A g=225 mp. (e=30,100) and 265 mp. (e=5760); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.65 5.85 and 6.10,u. Polar products are eluted by means of a. 4:1- mixture of benzene and ethyl acetate.

EXAMPLE A mixture of 0.104 g. of a-(2-carbo-tert.-butyloxy-3,3- dimethyl 7 oxo 4 thia 2,6 diaza-6-bicyclo[3,2,0] heptyl)-a-bromacetic acid 2,2,2-trichloroethyl ester and triphenylphosphine (1.3 equivalents) in 0.2 ml. of benzene at 25 yields at colorless precipitate within minutes. After one hour, the precipitate is filtered ofl, washed 4 times with 0.5 ml. of a 1:1-mixture of benzene 'and hexane and dried. The a-(Z-carbo-tert.-butyloxy-3,3- dimethyl 7 oxo 4 thia 2,6 diaza-6-bicyclo[3,2,0] heptyl -a- (triphenylphosphonium') -acetic acid 2,2,2-trichloroethyl ester bromide is thus obtained, which after treatment with an aqueous sodium carbonate solution yields the crude a-(2-carbo-tert.-butyloxy-3,3-dimethyl-7- oxo 4 thia 2,6 diaza '6 bicyclo[3,2,0]heptyl)-a- (triphenylphosphoranylidene)-acetic acid 2,2,2-trichloroethyl ester, M.P. 20l-202 after crystallization from hexane.

24- EXAMPLE 16 A solution of 0.115 g. of the crude mixture of the isomers of o: chloro a-(2u-isopropylmercapto-4-oxo-3a-N- phenyloxyacetylamino-1-azetidiny1)-acetic acid tert.-butyl ester in 2 ml. of dioxane is mixed with 0.12 g. of triphenylphosphine and 0.11 g. of polystyrene-Hiinig base and the mixture is stirred for 16 hours at 55, then filtered. The filter residue is washed 'with benzene and the filtrate is evaporated to dryness under reduced pressure. The residue is chromatographed on 5 g. of acid-washed silica gel. The excess triphenylphosphine is eluted with 40 ml. of benzene; the desired u-(2a-isopropylmercapto-4- oxo 3a N phenyloxyacetylamino 1 azetidinyl) atriphenylphosphoranylideneacetic acid tert.-butyl ester of the formula is obtained as a colorless oil by elution with a lzl-mixture of benzene and ethyl acetate, as well as with ethyl acetate; infrared absorption spectrum (in methylene chloride): characteristic bands at 3.05,u, 5.71;, 5.94,:4, 6.17 6.58 6.72,, 7.34 8.60;. and 9.03;.

EXAMPLE 17 A solution of 0.301 g. of u-(2-carbo-tert.-butyloxy-3,3- dimethyl 7 oxo 4 thia 2,6 diazo 6 bicyclo [3,2,0]heptyl) a (triphenylphosphoranylidene) acetic acid 2,2,2-trichloroethyl ester and 0.3 g. of liquid glyoxylic acid tert.-butyl ester (mainly in the form of the hydrate) is stirred for 22 hours at 50 and is then diluted with benzene and washed with water, dried and evaporated under reduced pressure. The crude product is taken up in benzene and is filtered through a column of 3 g. of acid-washed silica gel. The pure mixture of the isomers of u-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo-4- thia 2,6 diaza 6 bicyclo[3,2,0]heptyl) a (carbotert.-butyloxy-methylene)-acetic acid 2,2,2 trichloroethyl ester of the formula is obtained with ml. of benzene. Crystallization from ether yields the isomer A which after renewed recrystallization melts at 189; [a] =329:2 (c.=0.558 in chloroform); thin layer chromatogram (silica gel): Rf-0.64 in a 3:1-mixture of benzene and ethyl acetate; ultraviolet absorption spectrum (in ethanol): A =270 m (e=17,600); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.61;, 5.68 (shoulder), 5.75 (shoulder), 5.87 6.17 7.27;, 7.37;, 8.70;. and 9.32 Crystallization of the mother liquor residue from an ether-pentane mixture yields a crystalline isomer mixture, from which isomer 'B can be removed by washing out with cold ether; isomer B is obtained in fine needles from the filtrate after evaporation and crystallization from an ether-pentane mixture, M.P. 119-120";

(c.=1.213 in chloroform); thin layer chromatogram (silica gel): Rf-0.64 in a 3:1-mixture of benzene-ethyl acetate; ultra-violet absorption spectrum (in ethanol): A =279 mp. (e=8900); infrared absorption spectrum 25 (in methylene chloride): characteristic bands at 5.62,u, 5.75 s, S.87,u., 6.15% 73111., 8.65;.c, 9.05,u and 9.30,u.

The above reaction can also be carried out as follows: A solution of 5.04 g. of a-(Z-carbo-tenL-butyloxy-3,3-dimethyl 7 oxo 4 thia 2,6 diaza 6 bicyclo[3,2,0] heptyl)-u-(triphenylphosphoranylidene)-acetic acid 2,2,2- trichloroethyl ester in 15 ml. of absolute toluene, prepared at 60, is mixed with a solution of 4.5 g. of glyoxylic acid tert.-butyl ester in 10 ml. of absolute toluene while stirring in a nitrogen atmosphere, and is heated for hours at 60. After evaporation of the solvent under reduced pressure, the oily residue in benzene is filtered through a column (diameter: 3 cm.; height 32 cm.) of 100 g. of acid-washed silica gel. The pure mixture of isomers A and B of a-(2-carbo-tert.-butyloxy-3,3-dimethyl- 7 oxo 4 thia 2,6 diaza 6 bicyclo[3,2,0]heptyl)- a-(carbo-tert.-butyloxymethylene)-acetic acid 2,2,2-trichloroethyl ester is obtained with 500 ml. of benzene and an impure isomer mixture with a further 750 ml. of benzene. On crystallization according to the process described above the pure product yields the pure isomer A, M.P. 191; and the mother liquor yields the pure isomer B, M.P. 120-121"; a further quantity of the isomer B can be obtained from the impure mixture.

EXAMPLE 18 A mixture of 0.035 g. of a-(2-carbo-tert.-butyloxy-3,3- dimethyl 7 oxo 4 thia 2,6 diaza 6 bicyclo [3,2,0]heptyl) a (triphenylphosphoranylidene) acetic acid 2,2,2-trichloroethyl ester and 0.036 .g. of glyoxylic acid 2,2,2-trichloroethyl ester hydrate in 0.5 ml. of toluone is heated at 50 for 5 hours and under a nitrogen atmosphere. After diluting with benzene and washing with water, a residue is obtained from the organic solution which is purified by filtration thorugh 0.7 g. of acidwashed silica gel. The mixture of the two isomers of 06"(2' carbo tert. butyloxy 3,3 dimethyl 7 oxo 4 thia- 2,6 diaza 6 bicyclo[3,2,0]heptyl) oz (carbo 2,2,2,- trichloroethoxymethylene)-acetic acid 2,2,2-trichloroethyl ester of the formula G O OCHzC C 3 mo CHa is obtained by elution with ml. of benzene; thin-layer chromatogram (silica gel): Rf-0.7 in a 3:1-mixture of benzene and ethyl acetate. On crystallization from an ether-pentane mixture, an isomer is obtained as a crystalline product which melts at 176-177 and very probably has the configuration of maleic acid.

EXAMPLE 19 A solution of 0.212 g. of or (2-carbo-tert.-butyloxy- 3,3 dimethyl 7 oxo-4-thia-2,6-diaza-6-bicyclo[3,2,0] heptyl)-a(triphenylphosphoranylidene)-acetic acid 2,2,2- trichloroethyl ester in 0.5 g. of ethylene glycol dimethyl ether is reacted in a sealed glass tube with glyoxylic acid ethyl ester-hemiethyl acetal for 17 hours at 60. The mixture is then diluted with 1 ml. of xylene and evaporated under reduced pressure. The residue is chromatographed on silica gel (column of 1.8 cm. diameter and 20 cm. length), elution being carried out with a 95 :5- mixture of benzene and ethyl acetate. A 5:1-mixture of the two isomers of a-(2-carbo-tert.-butyloxy-3,3-dimethyl 7-oxo-4-thia-2,6-diaza-6-bicyc1o[3,2,0]heptyl)-a-carb ethoxymethylene)-acetic acid 2,2,2-trichloroethyl ester of the formula is thus obtained, which after recrystallization from pentane, melts at ultraviolet absorption spectrum (in ethanol); M :277 m (.e=10,550); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.65,u, 5.85,u, 5.90 and 620a.

EXAMPLE 20 A solution of 0.5 g. of tx-(2-carbo-tert.-butyloxy-3,3- dimethyl-7-oxo-4-thia-2,6-diaza-6-bicyclo [3 ,2,0] heptyl) -a- (triphenylphosphoranylidene)-acetic acid tert.-butyl ester in 5 ml. of dry dioxane is reacted for 1% hours with 0.6 g. of glyoxylic acid 2,2,2-trichloroethyl ester hydrate under a nitrogen atmosphere at 60. The solvent is then removed under reduced pressure; the residue is diluted with 10 ml. of benzene, whereupon the excess glyoxylic acid ester crystallizes out and is filtered OH. The filtrate is washed three times with 10 ml. of water and the washing liquids are backwashed with benzene and the organic solutions dried over sodium sulphate and evaporated. The crude product is chromatographed on silica gel (column of 1.8 cm. diameter and 15 cm. height), elution being carried out with 150 ml. of benzene, ml. of a 49:1- mixture and 100 ml. of a 19:1-rnixture of benzene and ethyl acetate. A 4:1-mixture of the two isomers of ca- (2 carbo-tert.-butyloxy 3,3-dimethyl-7-oxo-4-thia-2,6- diaza 6-bicyclo[3,2,0]heptyl) u-(carbo-2,2,2-trichloro ethoxymethylene)-acetie acid tert.-butyl ester of the formula is thus obtained. From the fractions containing primarily the isomer A, the latter is obtained by crystallization from pentane, M.P. 131; [a] =371i1 (c. =1.06l in chloroform); thin layer chromatogram (silica gel): Rf 0.5 in a 3:1-mixture of benzene and hexane; ultraviolet absorption spectrum (in ethanol): M :287 III/L (e=10,950); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.65 t, 5.83 5.90 and 6.20;! The other isomer shows an Rf-value of 0.3 in a thin layer chromatogram.

EXAMPLE 21 A mixture of 4 g. of a-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo-4-thia-2,6-diaza-6-bicyclo [3 ,2,0] heptyl x- (triphenylphosphoranylidene)-acetic acid tert.-butyl ester and 0.9 g. of glyoxylic acid hydrate in 80 ml. of absolute dioxane is kept for 3 hours at room temperature under a nitrogen atmosphere and is then evaporated under reduced pressure at a bath temperature of 45. The residue is dissolved in ml. of ether and three times extracted with 40 ml. of 1 N aqueous sodium carbonate solution each time. The aqueous extracts are washed with -150 ml. of ether, mixed with 20 ml. of a concentrated phosphate buffer solution (pH 6) and acidified to pH 6-5 with 63.2 ml. of 2 N aqueous sulphuric acid, and are then extracted four times with 150 ml. of ethereach time. The

27 ether extracts are dried over sodium sulphate and evaporated. The mixture of the isomers of a-(2-carbo-tert.- butyloxy 3,3 dimethyl-7-oxo-4-thia-2,6-diaza-6-bicyclo [3,2,0]heptyl) ot-(carboxymethylene)-acetic acid tert.- butyl ester of the formula is thus obtained, which consists of about 65% of the isomer A and about 35% of the isomer B. By chromatography on acid-washed silica gel and using a 4:1-mixture of hexane and ethyl acetate the isomer A is first eluted; M.P. 130 after three crystallizations from pentane; [a] =-457:1 (c=1 in chloroform; thin layer chromatography Rf=0.40 (silica gel; system toluene: acetic acidzwater 5:4: 1); ultraviolet absorption spectrum (in ethanol): A 277 m e=8850); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.65 5.80-5.95 and 6.25 then the isomer B, which after three crystallizations from pentane melts at 177; [a] =431:l (c.=l.041 in chloroform); thin layer chromatography (silica gel; system toluene: acetic acidzwater 5 :421: Rf=0.47; ultraviolet absorption spectrum (in ethanol: A 270 m (a: 17,000) infrared absorption spectrum (in methylene chloride): characteristic bands at 5.62 2, 5.805.95,LL and 6.25 (strong).

EXAMPLE 22 A solution of 2 g. of u-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo-4-thia-2,6-diaza-6-bicyclo [3 ,2,0] heptyl) -oc- '(triphenylphosphoranylidene)-acetic acid tert.-butyl ester and 0.7 g. of benzylglyoxal (in enol form) in 30 ml. of dry toluene is heated for 23 hours at 80 (bath temperature) in a nitrogen atmosphere, and is then mixed with a further quantity of 0.2 g. of benzylglyoxal; the mixture is heated for 22 hours at 80. The solvent is removed under reduced pressure and the viscous residue is chromatographed on a column of 60 g. of acid-washed silica gel. The excess benzylglyoxal is eluted with 450 ml. of benzene; a mixture of the isomers of ot-(2-carbo-tert.-butyloxy 3,3-dimethyl-7-oxo-4-thia-2,6-diaza-6-bicyclo[3,2,0] heptyl) a-(phenylacetylmethylene)-acetic acid tert.-butyl ester of the formula is eluted with 250 ml. (10 fractions) of a 95:5-mixture of benzene and ethyl acetate, and a polar material is eluted with a further quantity of the same solvent mixture.

The above mixture of isomers is again chromatographed on 60 g. of acid-washed silica gel, elution being carried out with a 99:1-mixture of benzene and ethyl acetate. A product consisting mainly of benzylglyoxal is obtained as the forerun, and then a fraction I consisting mainly of isomer A is obtained with 125 ml., a fraction II consisting of a mixture of both isomers with 250 ml., and a fraction III consisting mainly of isomer B with 300 ml. The above three fractions are recrystallized from hexane, whereupon fraction I yields isomer A; M.P. 109-1-10'; [a] =452i1 '(c.=1 in chloroform); thin layer chromatogram: Rf =0.49 (silica gel; system hexane: ethyl acetate, 2:1); ultraviolet absorption spectrum: a 297 mg (e=11,000) (in ethanol), 337 III/L (in potassium hydroxide/ ethanol) and 337 mg (on acidifying a basic solution in ethanol); infrared absorption spectrum (in methylene chloride) characteristic bands at 5.63 5.83,u (shoulder), 5 .855.95 t and 629 and fractions II and III yield isomer B; M.P. 157158; [u] =-363i0.7 (c.=1 in chloroform); thin layer chromatogram: Rf=0.42 (silica gel; system hexane: ethyl acetate, 2:1); ultraviolet absorption spectrum: x 294 my. (e=l9,300) (in ethanol), 335 m,u (potassium hydroxide/ethanol) and 335 my. (on acidifying a basic solution in ethanol); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.63,u., 5.80;; (shoulder), 5.84-5.96 and 634 Further quantities of the two isomers can be isolated from the mother liquors in the same manner.

EXAMPLE 23 A solution of 0.0162 g. of isomer B of a-(2-carbo-tert. butyloxy-3,3-dimethyl-7-oxo-4-thia-2,6-diaza 6 bicyclo [3,2,01-heptyl) a-(phenylacetylmethylene) acetic acid tert.-butyl ester in 10.6 ml. of benzene in a Pyrex glass vessel is irradiated with ultraviolet light at room temperature and under a nitrogen atmosphere. After minutes the solvent is distilled off; according to a nuclear resonance spectrum the noncrystalline residue consists of an approximately 42:58-mixture of isomer A and isomer B of a-(2-carbo-tert.-butyloxy 3,3 dimethyl 7-oxo-4-thia- 2,6-diaza-6-bicyclo[3,2,0] heptyl) a phenylacetylmethylene)-acetic acid tert.-butyl ester.

The crystalline isomer B and fractions which predominantly consist of isomer B of a-(2-carbo-tert.-butyloxy- 3,3-dimethyl-7-oxo 4-thia 2,6-diaza 6 bicyclo[3,2,0] heptyl)a-(phenylacetylmethylene) acetic acid tert.-butyl ester can in the same manner be isomerized to give isomer mixtures containing isomer A and isomer B of tit-(2- carbo-tert.-butyloxy-3,3-dimethyl-7-oxo 4 thia 2,6- diaza-6-bicyclo[3,2,0]heptyl)-u phenylacetylmethylene)- acetic acid tert.-butyl ester.

thia-2,6-diaza-6-bicyclo[3,2,0]heptyl) a. (triphenylphosphoranylidene)-acetic acid tert.-butyl ester is treated under nitrogen with 0.65 g. of isopropylglyoxal (in enol form) in 7 ml. of toluene and the mixture is allowed to stand for 8 days at 90. The solvent and the excess isopropylglyoxal are removed at 50 under reduced pressure and the residue is chromatographed on 50 g. of acid-washed silica gel; elution is carried out with a 4: l-mixture of hexane and ethyl acetate. The first ml. elute the isomer A (trans) of a- (2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo 4 thia 2,6- diaza-6 bicyclo[3,2,0]heptyl)-a-(isobutylryl-methylene)- acetic acid tert.-butyl ester of the formula which after crystallization from a mixture of hexane and ethyl acetate melts at 133-134"; ultraviolet absorption spectrum; A 294 m (in ethanol); X 330' mg (in potassium hydroxide/ethanol) and k 3301:. (in hydrogen chloride/ethanol); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.62 4, 5.80 (shoulder), 5.845.94 and 6.26,u.

The isomer B (cis) of a-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo 4 thia-2,6-diaza-6-bicyclo[3,2, 0]heptyl)- a(isobutyrylmethylene)-acetic acid tert.-butyl ester is obtained on further elution with the same solvent mixture and melts at 146l47 after crystallization from a mixture of hexane and ethyl acetate; ultra-violet absorption spectrum: A 289 m t (in ethanol); k 328 my. (in potassium hydroxide/ethanol); and A 328 mu (in hydrogen chloride/ethanol); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.60-5.66/L, 5.75, (shoulder), 5.855.95/L and 6.31 t.

EXAMPLE 25 A mixture of 0.05 g. of u-(2-carbo-tert.-butyloxy-3,3- dimethyl 7 oxo 4 thia-2,6-diaza 6-bicyclo[3,2,0] heptyl)-a-(triphenylphosphoranylidene) acetic acid tert.- butyl ester and 0.0355 g. of 4-nitrobenzyl-glyoxal in 0.6 ml. of toluene is heated for 7 hours at 80. The solvent is then distilled off under reduced pressure and the residue is chromatographed on a thin layer silica gel plate (20 x 20 x 0.15 cm.), using a 2:1-mixture of hexane and ethyl acetate. Two yellow bands are obtained, with the upper band yielding the isomer A of a-(2-carbo-tert.-butyloxy- 3,3-dimethyl-7-oxo 4 thia-2,6 diaza-6 bicyclo[3,2,0] heptyl)-u-[(4-nitro-phenylacetyl)-methylene] acetic acid tert.-butyl ester of the formula =o 1 1 C-CmQ-NO, CH3 CHCE ri l: ntc-h-o-c-N s 0 on, o c

HaC/ CH:

having an Rf-value=0.41; ultraviolet absorption spectrum: A 288 III/.L (broad; in ethanol) and A 505 mp. and 262 mu (potassium hydroxide/ethanol); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.63 1, 5.83 t (shoulder), 5.88-5.92 t, 5.97/L (shoulder), 6.28-6.33 t, 6.59 1. and 7.45 14 and the lower band yielding the isomer B of a-(2-carbo-tert.-butyloxy- 3,3 dimethyl 7 oxo-4-thia-2,6-diaza-6-bicyclo[3,2,0] heptyl) a-[ (4-nitro-phenylacetyl)-methy1ene]-acetic acid tert.-butyl ester of the formula as yellow glass-like products. Isomer B crystallizes from hexane, M.P. 173; Rf-value: 0.29; ultra-violet absorption spectrum: A 293 m t (in ethanol) and k 335 mu and 285 m (in potassium hydroxide/ethanol); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.62 t, 5.77 t (shoulder), 5.83-5.92/L, 6.30 6.35 1, 6.59,. and 7.45 1.

The 4-nitrobenzylglyoxal used above as the starting material can be manufactured as follows: A solution of about 4 g. of diazomethane in 200 ml. of dry ether is mixed dropwise, while stirring, with 6 g. of 4-nitrophenylacetyl chloride in 80 ml. of dry tetrahydrofuran, with the temperature being kept at 05 by stirring in a bath of ice-water. After about 30 minutes the addition is complete; the reaction mixture is stirred for a further 15 minutes at 0-5" and is then evaporated in a rotational evaporator. The solid residue is dissolved in a mixture of methylene chloride and ether and the small amount of solid material is filtered oil? and the filtrate is evaporated. The 4-nitrobenzyl-diazomethylketone is thus obtained, which after crystallization from a mixture of ether and hexane melts at 90-92"; infrared absorption spectrum (in methylene chloride): characteristic bands at 4.78 t, 6.10 1, 6.26 1, 6.58 1 and 7.45 t.

A solution of 3 g. of 4-nitrobenzyl-diazomethyl-ketone in 100 ml. of a lzl-mixture of ether and methylene chloride is mixed with a solution of 4.22 g. of triphenylphosphine in ml. of ether. After about 5 minutes the 1-(4- nitrophenyl) 3 (triphenylphosphoranylidene hydrazono)-acetone crystallizes out at room temperature; the mixture is filtered and the mother liquor is concentrated to yield a further quantity of the crystalline product. The crude product is crystallized from a mixture of 50 ml. of methylene chloride and 250 ml. of hexane, M.P. ultraviolet absorption spectrum (in ethanol): 320 mi and 270-275 III/L (shoulder); infrared absorption spectrum (in methylene chloride): characteristic bands at 6.10 t (shoulder), 6.14-6.20 6.32 1, 6.67-6.74 and 7.45 1.

A suspension of 0.467 g. of 1-(4-nitrophenyl)-3-(triphenyl-phosphoranylidene-hydrazono)-acetone in 3 ml. of tetrahydrofuran is mixed with 0.21 g. of pulverized sodium nitrite and 1.2 ml. of water. The mixture is cooled to 05 and 2.2 ml. of 2 N hydrochloric acid are added dropwise over the course of 2 minutes, whereupon an emulsion forms. After 60 minutes at 0-5", the aqueous layer is separated and extracted four times with 10 ml. of methylene chloride at a time. The combined organic solutions are twice washed with 10 ml. of a saturated aqueous chloride solution each time and are evaporated; the residue is chromatographed on 20 g. of acid-washed silica gel. The crystalline and enolized 4-nitrobenzylglyoxal, M.P. 163-164", is eluted with 600 ml. of benzene; ultraviolet absorption spectrurnzx 343 m t (in ethanol); 444 mu (in potassium hydroxide/ethanol) and A 343 11114 (in hydrogen chloride/ethanol):infrared absorption spectrum (in methylene chloride) :characteristic bands at 3.02 t, 5.98 1, 6.06,.L, 6.28 t, 6.60/L and 7.47 t; whereas the hydrate of 4-nitrobenzylglyoxal is eluted as a noncrystalline syrupy material with 350 ml. of a 9:1-mixture of benzene and ethyl acetate; infrared absorption spectrum (in methylene chloride): characteristic bands at 3.01 t, 5.82 t, 6.27 t, 6.61 1. and 7.47 t.

EXAMPLE 26 A mixture of 0.872 g. of a-(2-carbo-tert.-butyloxy- 3,3 dimethyl 7 oxo-4-thia-2,6-diaza-6-bicyclo[3,2,0] heptyl)-a-(triphenylphosphoranylidene)-acetic acid tert.- butyl ester and 0.611 g. of 4-nitrobenzylglyoxal hydrate in 10.5 g. of toluene is heated at 80 for 6 /2 hours. The solvent is distilled off under reduced pressure and the residue is chromatographed on 50 g. of acid-washed silica gel. The isomer A of a-(2-carbo-tert.-butyloxy-3,3-dimethyl 7 oxo-4-thia-2,6-diaza-6-bicyclo[3,2,0]heptyl)- a [*(4 nitrophenylacetyl)-methylene]-acetic acid tert.- butyl ester is eluted with 1300 ml. of benzene and 500 ml. of a 98.5 1.5-mixture of benzene and ethyl acetate, a mixture of the two isomers A and B of u-(2-carbo-tret.-butyloxy 3,3 dimethyl 7 oxo-4-thia-2,6-diaza-6-bicyclo- [3,2,0]heptyl) 0c [(4-nitro-phenylacetyl)-methylene]- acetic acid tert.-butyl ester is eluted with 200 ml. of a 96:4-mixture of benzene and ethyl acetate, and isomer B of u-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo-4-thia-2,6- diaza 6 bicyclo[3,2,0]heptyl) a [(4-nitro-phenylacetyl)-methylene]-acetic acid tert.-buty1 ester together with a small quantity of isomer A is eluted with a further 400 ml. of the 96:4mixture of benzene and ethyl acetate. The mixture is separated by means of thin layer chromatography (4 silica gel plates: 20 x 20 X 0.15 cm.) using a 2:1-mixture of hexane and ethyl acetate; one thus ob tains a further quantity of isomer A; Rf=0.41; and of isomer B; Rf=0.29. The latter is combined with the almost pure isomer B from the chromatogram and crystallized from hexane, M.P. 173.

EXAMPLE 27 A mixture of 0.714 g. of u-(2-carbo-tert.-butyloxy-3,3- dimethyl 7 oxo 4 thia-2,6-diaza'-6-bicyclo[3,2,0] heptyl) a (triphenylphosphoranylidene) acetic acid tort-butyl ester and 0.67 g. of 4-methoxybenzylglyoxal hydrate in 8.6 m1. of toluene is heated at 80 for 3 /2 hours and is then evaporated under reduced pressure. The residue is chromatographed on 50 g. of acid-washed silica gel. The excess 4-methoxybenzyl-glyoxal is eluted in an anhydrous form with 500 ml. of benzene while with 800 ml. of a 99:1-mixture of benzene and ethyl acetate the almost pure isomer A of a-(2-carbo-tert.-butyloxy-3,3-dimethyl 7 oxo 4-thia-2,6-diaza-6-bicyclo[3,2,0] heptyl)- on [(4-methoxy-phenylacetyl)-methylene] acetic acid tert.- butyl ester of the formula (IJOOC(CH:4)=

is eluted; M.P. 105-107 after recrystallization from a mixture of ethyl acetate and hexane; ultraviolet absorption spectrumzk 298 m 288 my (shoulder) and 225 m,u (shoulder) (in ethanol) :A 340 my. (in potassium hydroxide/ethanol); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.63 5.82,:1. (shoulder), 5.87-5.97 6.23 (shoulder), 6.28;, 6.63 and 6.77 with a further 400 ml. of the 99: l-mixture of benzene and ethyl acetate, a mixture of the isomers A and B is eluted, and with 300 ml. of a 98:2-mixture of benzene and ethyl acetate the isomer B of oc-(Z-CEIPbO- tert.-butyloxy-3,3-dimethyl 7 x0 -4 thia -2,6 diaza 6 bicyclo[3,2,0]heptyl) oz [(4 methoxy phenylacetyl)-methylene]-acetic acid tert.-buty1 ester of the formula is eluted; the pure isomer B obtained from the mixed fraction by recrystallization from hexane, and the pure isomer B obtained in the same manner from the isomer B fraction melt at 169170; ultraviolet absorption spectrum: A 289 mu (broad) and 227 m (shoulder) (in ethanol); and A 343 m,u (in potassium hydroxide/ethanol); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.59,u, 5.75 1. (shoulder), 5.80-5.93 6.24,u (shoulder), 6.30 and 6.60a-

Further quantities of the two isomers A and B of u- (2-carbo-tert.-butyloxy 3,3 dimethyl -7 oxo 4 thia 2,6 diaza 6 bicyclo[3,2,0]heptyl) a [4 -methoxy phenylacetyl) methylene] acetic acid tert.-butyl ester can be obtained from the combined mother liquors by means of preparative thin layer chromatography and development with a 2:1-mixture of hexane and ethyl acetate.

The 4-methoxybenzylglyoxal hydrate used as the starting material in the above example can be obtained as follows:

A solution of 7.43 g. of 4-methoxy-phenylacetyl chloride in 100 ml. of dry ether is added dropwise to a solution of 6 g. of diazomethane in 300 ml. of ether cooled to 0-5 The reaction mixture is stirred .for a further 30 minutes, finally without cooling. The excess diazomethane and the solvent are removed under reduced pressure in a rotational evaporator, the residue is dissolved in 100 ml. of ether, and the small amount of wax-like material is filtered 01f. After evaporation of the filtrate, the 4- methoxybenzyl-diazomethyl ketone is obtained; infrared absorption spectrum (in methylene chloride): characteristic bands at 4.79;, 6.10,, 6.22;; (shoulder), 6.62 and 7.73-7.45 this material is further processed without purification.

A solution of 7.52 g. of 4-methoxybenzyl-diazomethylketone in 300 ml. of ether is mixed with 11.1 g. of triphenylphosphine in 200 ml. of ether. The reaction mixture is stirred at room temperature, whereupon a crystalline precipitate forms after a few minutes; this is filtered off after one hour and washed with cold ether. The 1-(4- methoxyphenyl) 3 (triphenyl phosphoranylidene hydrazono)-acetone, M.P. Ill-112, is thus obtained; infrared absorption spectrum (in methylene chloride): characteristic bands at 4.80 6.05 (shoulder), 6.14;. 6.24 4 (shoulder), and 6.636.70,u; this is processed without further purification.

A solution of 1.82 g. of 1-(4-methoxyphenyl)-3-(triphenylphosphoranylidene-hydrazono)-acetone in 12 ml. of tetrahydrofuran is mixed with 0.84 g. of pulverized sodium nitrite and the mixture is diluted with 5 ml. of water. The resulting suspension is cooled to 0-5, treated dropwise over the course of 7 minutes with 8.8 ml. of 2 N hydrochloric acid and then kept for a further 30 minutes at 0-5. The aqueous phase is twice washed with methylene chloride; the combined organic solutions are washed with a saturated aqueous sodium chloride solution, dried over sodium sulphate and evaporated under reduced pressure. The oily residue is chromatographed on 40 g. of acid-washed silica gel. A small quantity of a by-product is eluted with benzene and, using 1200 ml. of a 95 :5- mixture of benzene and ethyl acetate, the 4-methoxybenzylglyoxal is obtained in the .form of the hydrate, which is an oily product; infrared absorption spectrum (in methylene chloride): characteristic bands at 2.96 1, 5.79-5.84a, 6.23,u. and 6.63,u. The anhydrous product melts at l39-l40 after recrystallization from a mixture of chloroform and hexane; ultra-violet absorption spectrum: A 333 III/1. (in ethanol or hyrdochloric acid/ ethanol) and 367 m (in potassium hydroxide/ ethanol); infrared absorption spectrum (in methylene chloride): characteristic bands at 3.00 9, 5.97,, 6.09.14. 6.24 6.61# and 7.15;.

EXAMPLE 28 A solution of 0.8 g. of a-(2-carbo-tert.-butyloxy-3,3- dimethyl-7 oxo 4 thia 2,6 diaza -6 bicyclo[3,2,0] heptyl)-u-(triphenylphosphoranylidene)-acetic acid tert.- butyl ester and 1.2 g. of crude 4-chlorobenzyl-glyoxal hydrate in 12 ml. of toluene is heated at for 5 hours. The solvent is distilled oif under reduced pressure, and the syrupy residue is dissolved in about 4 ml. of benzene. The resulting crystalline precipitate, consisting of the enol of 4-chlorobenzylglyoxal, is filtered off and the filtrate is chromatographed on a column of 50 g. of acid-washed silica gel. A further quantity of 4-chlorobenzyl-glyoxal is eluted with 500 ml. of benzene, and a mixture of the isomers of a-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo- 4-thia-2,6-diaza-6-bicyclo[3,2,0]heptyl)-a [(4 chloro phenylacetyl)-methylene]-acetic acid tert.-butyl ester eluted with 200 ml. of benzene and 800 ml. of a mixture of benzene and ethyl acetate (97:3) the reaction mixture is chromatographed on a further 50 g. of acid-washed silica gel by means of benzene and benzene containing 5% of ethyl acetate, and then separated by preparative thin-layer chromatography (system hexanezethyl acetate 2:1). There is obtained the non-crystalline isomer A (trans) of a-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo- 4-thia-2,6 diaza 6 bicyclo[3,2,0]heptyl)-u-[(4-ch10 rophenylacetyl)-methylene]-acetic acid tert.butyl ester of the formula which shows the following bands in the ultraviolet absorption spectrum k 300 mg (in ethanol); )t 342 m;; (in potassium hydroxide/ethanol); and A 338 mg (on the addition of hydrogen chloride to the preceding sample); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.60;, 5.75;; (shoulder), 580-592;; (broad), 6.26;; and 6.70% and the crystalline isomer B (cis) of a-(2-carbo-tert.-butyloxy- 3,3 dimethyl 7 oxo 4 thia 2,6 diaza 6 bicyclo- [3,2,0]heptyl) a [(4 chlorophenyl-acetyl) methylene]-acetic acid tert.-butyl ester of the formula which, after recrystallization from hexane, melts at 178- 179; ultraviolet absorption spectrum: A 295 my (in ethanol); A 337 mp. (in potassium hydroxide/ethanol); and k 337 mg (on the addition of hydrogen chloride to the preceding sample; infrared absorption spectrum (in methylene chloride): characteristics bands at 5.05;, 5.75;; (shoulder), 5.78-5.94;;.; 6.07;; (shoulder), 6.31;; and 6.70 The isomer A is processed without further purification.

The 4-chlorobenzyl-glyoxal hydrate may be prepared as follows:

A solution of 16.5 g. of 4-chloro-phenylacetyl chloride in 150 ml. of dry ether is added dropwise, with vigorous stirring and cooling in an ice-water bath, to about 11 g. of diazo-methane in 500 ml. of ether. After being allowed to react for 30 minutes at -10, the diazomethane and the solvent are distilled off under reduced pressure. The 4-chlorobenzyl diazomethyl ketone obtainable as a yellowish crystalline residue; infrared absorption spectrum in methylene chloride: characteristic bands at 4. 84 6.22;;, 6.80 1. and 7.47;; is processed without any further purification.

A solution of 17 g. of 4-chlorobenzyl diazomethyl ketone in 150 ml. of ether is added at room temperature to a solution of 23.5 g. of triphenyl phosphine in 300 ml. of ether. The yellowish crystalline precipitate is filtered off after 20 minutes, washed with ether and recrystallized from a mixture of methylene chloride and ether; the resulting l-(4-chlorophenyl)-3-(triphenylphosphoranylidene-hydrazono)-acetone melts at 130-131; ultraviolet absorption spectrum: A 320 mu (ethanol); A 320 my. (potassium hydroxide ethanol); and X 255-278 mg (broad shoulder) (in hydrogen chloride/ ethanol); infrared absorption spectrum (in methylene chloride): characteristic bands at 4.76;;, 6.03;; (shoulder), 6.12;;, 6.28;; (shoulder) and 6.65-6.75

A suspension of 8 g. of 1-(4-chlorophenyl)-3-(triphenylphosphoranylidene-hydrazono)-acetone and 3.6 g. of sodium nitrite in 51 ml. of tetrahydrofuran and 22 ml. of water is treated dropwise in the course of about 10 minutes with 37 ml. of 2 N hydrochloric acid while stirring and cooling in an ice-water bath (IO-13), two phases being formed. Stirring is continued for 30 minutes at room temperature, the organic layer is separated, and the aqueous phase is extracted several times with methylene chloride. The combined organic solutions are dried over sodium sulphate and evaporated under reduced pressure. A syrupy residue is obtained which is chromatographed on 60 g. of acid-washed silica gel. The crude 4- chlorobenzylglyoxal hydrate is extracted with benzene and a 95:5-mixture of benzene and ethyl acetate, ultraviolet absorption spectrum: A 222 mg (in ethanol); )t 365 my. (in potassium hydroxide/ethanol); and A 316 m (in hydrogen chloride/ethanol); infrared absorption spectrum (in methylene chloride): character- 34 istic bands at 2.87-4.3u, 5.77 6.27;; and -6.72;t; the product is processed without any further purification. The anhydrous 4-chlorobenzyl-glyoxal in the enol form melts after recrystallization from methylene chloride at 144-147"; ultraviolet absorption spectrum; A 316 m (in ethanol); A 364 my. (in potasium hydroxide v -}ethanol); and A 326 m (in hydrogen chloride +ethanol); infrared absorption spectrum (in methylene chloride): characteristic bands at 2.92;;, 5.97;, 6.07;, 6.29 and 6.71m

EXAMPLE 29 A solution of 2.5 g. of a-(2-carbo-tert.-butyloxy-3,3- dimethyl 7 oxo 4 thia 2,-6 diaza 6 bicyclo- [3,2,0]heptyl) a (triphenylphosphoranylidene)-acetic acid tert.-butyl ester and 1.3 g. of cyclohexylmethylglyoxal hydrate in 50 ml. of toluene is heated for 4 hours at and the solwent is evaporated under reduced pressure. The syrupy residue is triturated with ether, the resulting triphenyl phosphinoxide is filtered off and the filtrate is evaporated. The residue is chromatographed on g. of acid-washed silica gel and eluted with a 98:2- and a 9:1-mixture of hexane and ethyl acetate, to yield first the isomer A (trans) of a-(2-carbo-tert.-butyloxy- 3,3 dimethyl 7 oxo 4 thia 2,6 diaza 6 bicyclo- [3,2,0]heptyl) a (cyclohexyl-acetyl-methylene)-acetic acid tert.-butyl ester of the formula H \C/ on, (EH-on d-cm-O HaC- o-o-N s ii (3H3 ii o HsC CHs which is purified by means of preparative thin-layer chromatography (plates 20 x 20 x 0.15 cm.; silica gel; system benzenezacetone 98:2) and is obtained in a syrupy form; optical rotation [u] =-451:':.1 (c=0.87 in chloroform); ultraviolet absorption spectrum; A 297 my. (in ethanol); A 334 m (in potassium hydroxide/ethanol); and A 334 m (on the addition of hydrogen chloride to the alkaline sample); infrared absorption spectrum (in methylene chloride); characteristic bands at 3.45u, 3.50,, 5.16;u, 5.78;; (shoulder), 5.80;, 5.95,u., 6.07 (shoulder) and 628g.

The isomer B (cis) of m-(2-carbo-tert.-butyloxy-3,3- dimethyl-7-oxo-4-thia 2,6-diaza-6-bicyclo[3,20]heptyl)- a-(cyclohexylacetyl methylene)-acetic acid tert.-butyl ester of the formula is eluted as second product and crystallized from hexane; M.P. 154-155; optical rotation [a] =232:1 (c.=0.8 in chloroform); ultraviolet absorption spectrum: A 288 mg (in ethanol), A 333 m (in potassium hydroxide/ethanol) and )l 333 m (on addition of hydrogen chloride to the above alkaline sample); infrared absorption spectrum (in methylene chloride): characteristic bands at 3.44;, 3.53 5.60 5.75; (shoulder), 5.80- 593 6.05;; (shoulder) and 6.3m.

The cyclohexamethylglyoxal hydrate used as starting material may be prepared as follows:

A solution of 19.8 g. of cyclohexylacetyl chloride (B.P. 98-100/23 mm. Hg) in ml. of dry ether is slowly added at 0-5 with cooling in an ice-water bath to a vigorously stirred solution of 11 g. of diazomethane in 500 ml. of ether. The excess diazomethane and ether is distilled off under reduced pressure and cyclohexylmethyl diazomethyl ketone is obtained as residue; infrared absorption spectrum (in methylene chloride): characteristic bands at 3.45 3.52;, 4.75 1. and 6.12 the product is processed without any further purification.

A solution of 20 g. of cyclohexalmethyl diazomethyl ketone in 100 ml. of ether is added in one portion, with stirring, to a solution of 32 g. of triphenylphosphine in 450 ml. of ether. After stirring for 30 minutes at room temperature, the solvent is evaporated under reduced pressure. The 1-cyclohexyl-3-(triphenylphosphoranylidenehydrazono)-acetone obtainable as oily residue crystallizes in the cold from ether; M.P. 58-62; ultraviolet absorption spectrum: k 314 mp, 262-275 mg and 223 Inn (in ethanol and in potassium hydroxide/ethanol), and A 257-275 mp. and 230 my (in hydrogen chloride/ ethanol); infrared absorption spectrum (in methylene chloride): characteristic bands at 3.43 3.56 4.76;. 6.15 1. and 6.67%

77 ml. of 2 N hydrochloric acid are added slowly, with stirring and cooling to 10-13 (ice-water bath), to a mixture of 15 g. of l-cyclohexyl-3-(triphenylphosphoranylidene-hydrazono)-acetone and 7.37 g. of sodium nitrite in 120 ml. of tetrahydrofuran and 42 ml. of water. After another 30 minutes at room temperature the organic solution is separated and the aqueous phase is extracted with methylene chloride. The combined organic solutions are dried over sodium sulphate and evaporated under reduced pressure. The syrupy residue is treated with ether, the resulting triphenyl phosphinoxide is filtered off and the filtrate is evaporated. The residue is chromatographed on a column of 120 g. of acid-washed silica gel, elution being carried out with about 3000 ml. of a 97:3-mixture of hexane and ethyl acetate to yield the cyclohexylmethyl-glyoxal hydrate as a syrupy product; infrared absorption spectrum (in methylene chloride): characteristic bands at 2.90-4.1a (broad); 3.47 1. 3.53;: and 5 .80 the product is further processed without purification.

EXAMPLE 30 A solution of 2.55 g. of the mixture of the isomers of a-(2-carbo-tert.-butyloxy-3,3-dimethyl 7-oxo-4-thia- 2,6-diaza 6-bicyclo[3,2,0]heptyl)-u (carboxymethylene)-acetic acid tert.-butyl ester in 80 ml. of a 9:1-mixture of acetic acid and water is mixed every 15 minutes with 0.5 g. of zinc dust at room temperature, and with vigorous stirring, until the reduction is complete. After one hour, only a small quantity of starting material can still be detected; the addition of zinc dust is interrupted and the mixture is stirred for a further 2 hours at room temperature and then mixed with 60 ml. of water and 60 ml. of methylene chloride. It is filtered through cottonwool and then extracted four times with 100 ml. of methylene chloride at a time. The combined methylene chloride solutions are dried over sodium sulphate and evaporated at 45 under reduced pressure. The

. residue is repeatedly mixed with benzene and the latter is evaporated each time until the acetic acid is completely removed. The crude residue is filtered through acidwashed silica gel (diameter: 4 cm.; height: 10 cm.), el-ution being carried out with a 2:1-mixture of hexane and ethyl acetate; the mixture of the isomers of a-(2- carbo-tent.-butyloxy-3,3 dimethyl-7-oxo-4-thia-2,6-diaza- 6-bicyclo[3,2,0]heptyl) or (carboxymethyD-acetic tert.- butyl ester of the formula is thus obtained; this can be separated almost completely by crystallization from ether and hexane. The isomer A is first obtained, and melts in a somewhat impure form, after recrystallization from an ether-hexane mixture, at l69-171; analytical sample: M.P. 172-173"; [a] =295 i1 (c.=1.l68 in chloroform); thin layer chromatography (silica gel; system toluene:acetic acid: water 5:4:1): Rf=0.35; infrared absorption spectrum (in methylene chloride): characteristic bands at 5.68 5.72;]. and 5.90,u.

The first mother liquor predominantly contains isomer B which can be purified as follows: A solution of 0.1983 g. of the mother liquor residue containing isomer B in 5 ml. of methylene chloride is mixed with 2.26 ml. of a solution of 1.9836 g. of cyclohexylamine in ml. of ether and the solution is evaporated. The residue is taken up in methylene chloride and filtered, the filtrate is evaporated and the residue is crystallized from a mixture of methylene chloride and acetone. The crystalline material obtainable in this way and that from the first working-up of the mother liquor are dissolved in 5 ml. of methylene chloride, shaken with 5 ml. of water containing 0.5 ml. of 2 N sulphuric acid and the aqueous phase is back-washed with 10 ml. of methylene chloride. The organic solutions are washed with 10 ml. of water, dried over sodium sulphate and evaporated; the pure isomer B of a-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo- 4-thia-2,6-diaza 6-bicyclo[3,2,0]heptyl) u-(carboxymethyl)-acetic acid tert.-butyl ester is thus obtained, M.P. 116-117; [-a] =252i1 (c.=0.924 in chloroform); thin layer chromatography (silica gel; system toluene:acetic acid:water 5:421): Rf=0.33; infrared absorption spectrum (in methylene chloride): characteristic bands at 5.68;, 5.78 and 5.85-5.90 t.

EXAMPLE 31 A solution of 0.065 g. of the isomer mixture of a-(2- canbo-tert.-butyloxy 3,3 dimethyl 7 oxo-4-thia- 2,6 diaza 6 bicyclo[3,2,0]heptyD-a-(carbethoXymethylene)-acetic acid 2,2,2-trichloroethyl ester in 2 ml. of a 4:1-mixture of hexane and methylene chloride is mixed at room temperature, in a carbon monoxide-nitrogen atmosphere, with about 2 mol equivalents of cobalt hydrocarbonyl in hexane over the course of one hour. The reducing reagent is manufactured as follows: A solution of 0.39 g. of dicobaltoctacarbonyl in 10 ml. of dry hexane is mixed with 3 ml. of dimethylformamide under a nitrogen atmosphere and is stirred for half an hour. A two-phase system is obtained; the upper layer is colourless and the lower layer is red. 8 ml. of a 1:1-mixture of concentrated hydrochloric acid and 2 N hydrochloric acid are then added while cooling in an ice bath and the mixture is stirred for one hour at 0. The blue acid layer is separated and the yellow hexane solution is Washed three times with 1 ml. of water. The hexane solution contains 1.47 mmols of cobalt hydrocarbonyl of the formula H-Co(CO) and is used in this form.

The reaction mixture is then filtered through a column (height: 7 6111;; diameter: 2 cm.) of silica gel and is eluted with benzene (cobalt derivative) an-d with 20 ml. of a 3:1-mixture of benzene and ethyl acetate. From the latter mixture a crude product is obtained which is again chromatographed on silica gel and eluted with 49:1-, 19:1- and 4:1-mixtures of benzene and ethyl acetate. The isomer A of a-(2-carbo-tert.-butyloxy-3,3- dimethyl 7 oxo 4 thia 2,6-diaza-6-bicyclo[3,2,0]

heptyl)-a-(carbethoxymethyl)-acetic acid 2,2,2-trichloroethyl ester of the formula COOCHZCCII H \CH:COOC2H5 CH: JH-C IH HaC-(J-O-C-N \S (EH3 \C/ H36 \CHI 37 M.P. 90 after crystallization from pentane, and a mixture of isomer B with small amount of isomer A, as well as a small quantity of 2-carbo-tert.-butyloxy-3,3-dimethyl- 4-thia-2,6-diaza-bicyclo[3,2,0]heptan-7-one are obtained.

EXAMPLE 32 A hexane solution of 1.47 mmols of cobalt hydrocarbonyl is mixed with 0.2 g. of a-(2-carbo-tert.-butyloxy- 3,3 dimethyl 7 oxo 4 thia-2,6-diaza-6-bicyclo- [3,2,0]heptyl) or (carbo-tert.-butyloxy-methylene)- acetic acid 2,2,2 trichloroethyl ester in 2 ml. of a 4:1- mixture of hexane and methylene chloride; the reaction mixture turns dark brown. After standing for 30 minutes at room temperature, it is filtered through silica gel. The cobalt compounds are eluted with benzene until the silica gel is colourless and elution is then carried out with a 9:1-mixture of benzene and ethyl acetate, whereby a mixture of the isomers of a-(2-carbo-tert.-butyloxy-3,3- dimethyl 7-oxo-4-thia-2,6-diaza-6-bicyclo[3,2,0]heptyl)- a-(carbo-tert.-butyloxymethyl)-acetic acid 2,2,2-trichloroethyl ester of the formula oooomccu is obtained, while 2-carbo-tert.-butyloxy-3,3-dimethyl-4- thia 2,6 diaza-bicyclo[3,2,0]heptan-7-0ne is eluted With a 3:1-mixture of benzene and ethyl acetate. After crystallization from a mixture of methylene chloride and pentane, the mixture of the two isomers melts at 95- 105, and after a further crystallization the isomer A, M.P. 108, is obtained; [a] =240i1 (c.=0.452 in chloroform); ultraviolet absorption spectrum (in ethanol): A =230 m (weak); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.65 5.70 s, 5.85/1. and 590 EXAMPLE 33 A mixture of 0.0414 g. of a-(2-carbo-tert.-butyloxy- 3,3 dimethyl 7 oxo 4 thia-2,6-diaza-6-bicyclo- [3,2,0]heptyl) a (carbo-tert.-butyloxy-methylene)- acetic acid 2,2,2-trichloroethyl ester in 4 ml. of ethyl acetate is hydrogenated for 45 minutes under atmospheric pressure at 30 in the presence of 0.0524 g. of a 10% palladium-on-charcoal catalyst. After filtration, the filtrate is evaporated and the residue is purified by filtration through 1.2 g. of acid-washed silica gel. A polar material is eluted with 15 ml. of benzene and the bulk of the isomer mixture of a-(2-carbo-tert.-butyloxy-3,3-dimethyl 7 oxo -4 thia 2,6 diaza-6-bicyclo[3,2,0] heptyl)-u-(carbo-tert.-butyloxy-methyl)-acetic acid 2,2,2- trichloroethylester with 5 ml. of a 9:1-mixture of benzene and ethyl acetate; after crystallization from pentane,

it melts at 90-96".

EXAMPLE 34 A solution of 1.98 g. of 'dicobalt octacarbonyl in 25 ml. of hexane is mixed with 6 ml. of dimethylformamide while stirring in a nitrogen atmosphere. After 30 minutes, two phases, an upper yellow phase and a lower red phase, are formed. The mixture is cooled to mixed with 10 ml. of a lzl-mixture of 2 N hydrochloric acid and concentrated hydrochloric acid while stirring, and kept for one hour at about 0. The blue acid layer is separated and the remaining mixture is washed three times with ml. of water and then dried with a small amount of sodium sulphate.

A solution of 1.039 g. of a-(2-carbotert.-butyloxy-3,3- dimethyl 7 oxo 4 thia-2,6-diaza-6-bicyclo[3,2,0] heptyl)-u-(carbo-tert.-butyloxy-methylene)acetic acid 2, 2,2-trich1oroethy1 ester in 3 ml. of methylene chloride and 4 ml. of n-hexane is mixed, in a nitrogen atmosphere, with the cobalt hydrocarbonyl solution prepared according to the above process, and the mixture is stirred for 15 minutes at room temperature and is then filtered through acid-washed silica gel. The column (diameter: 2 cm.; height: 25 cm.) is Washed with benzene until colourless and the mixture of isomers of a-(2-carbo-tert.- butyloxy 3,3 dimethyl 7 oxo 4 thia-2,6-diaza-6- bicyclo[3,2,0]heptyl) a (carbo-tent.-butyloxymethyl)- acetic acid 2,2,2-trichloroethyl ester is then eluted with a 19:1-mixture of benzene and ethyl acetate. Isomer A, M.P. IDS-, is obtained by repeated crystallization from pentane; the mother liquor mainly contains a 1:1-mixture of the two isomers. The isomer A has the following configuration A solution of 0.205 g. of a-(2-carbo-tert.-butyloxy-3,3- dimethyl 7 oxo 4 thia-2,6-diaza-6-bicyclo[3,2,0]heptyl)-a-(carbo-tert.-butyloxymethylene)-acetic acid 2,2,2- trichloroethyl ester (mixture of both isomers) in 6 ml. of a 4:1-mixture of hexane and methylene chloride is mixed, at room temperature and under a nitrogen atmosphere, with 3 equivalents of cobalt hydrocarbonyl in 10 ml. of hexane and the mixture is then filtered through a column of silica gel (2 cm. of diameter and 8 cm. length), with the cobalt compounds being eluted with benzene and the reduction products being eluted with a 3:1-mixture of benzene and ethyl acetate. The crude product is again filtered through silica gel (column diameter: 1 cm.; height: 25 cm.), with a forerun being eluted with 100 ml. of benzene, and isomer of the starting material being eluted with ml. of a 99:1-mixture of benzene and ethyl acetate, the isomer B of u-(Z-carbotert.-butyloxy-3,3-dimethyl-7-oxo-4-thia 2,6 diaza-6- bicyclo[3,2,0]heptyl) a (carbo-tert.-butyloxymethyl)- acetic acid 2,2,2-trichloroethyl ester, followed by a mixture of the two isomers and the pure isomer B being eluted with 200 ml. of 49: l-mixture of benzene and ethyl acetate, and a small quantity of 2-carbo-tert.-butyloxy- 3,3-dimethyl 4 thia 2,6 diaza-bicyclo[3,2,0]heptan- 7-one then being eluted with 80 ml. of a 4:1-mixture of benzene and ethyl acetate. The isomer B has the following configuration and melts at 92-93 after crystallization from pentane; [a] '--197:1 (c.=0.555 in chloroform); ultraviolet absorption spectrum (in ethanol): weak absorption at 230-240 mg; infrared absorption spectrum (in methylene chloride): characteristic bands at 5.65,u., 5.725p and 5.855.95p..

EXAMPLE 36 A mixture of 0.035 g. of isomer A of a-(2-carbo-tert.- butyloxy 3,3 dimethyl 7 0x0 4 thia 2,6 diaza- 6 bicyclo[3,2,0]heptyD-a-(carbo-tert.-butyloxymethyl)- acetic acid 2,2,2-trichloroethyl ester (Example 34) and 2 ml. of precooled trifluoroacetic acid is allowed to stand for 25 minutes at 0 and is then evaporated in a high vacuum and mixed with 3 ml. of a saturated aqueous solution of sodium acetate. The reaction mixture is extracted with methylene chloride and the organic solution is dried over sodium sulphate and evaporated. The residue crystallizes from a mixture of ether and pentane and yields the a-(3,3 dimethyl-7-oxo-4-thia-2,6-diaza-6-bicyclo[3,2,0]heptyl) a (carbo-tert.-butyloxy-methyl)- acetic acid 2,2,2-trichloroethyl ester of formula o=e--1;: om-o o o owns;

on on HN s Hac CH which melts at 136138; [a] 1l2i2 (c. =0.625 in chloroform); thin layer chromatography (silica gel): Rf=0.25 in a 3:1-mixture of benzene and ethyl acetate; infrared absorption spectrum (in methylene chloride): characteristic bands at 2.12 14, 5.74 5.84 and 7.34pm

EXAMPLE 37 A mixture of 0.75 g. of the isomer mixture of a-(2- carbo-tert.-butyloxy 3,3 dimethyl 7 oxo 4 thia- 2,6-diaza-6-bicyclo[3,2,0]heptyl) a (carboxymethylene)-acetic acid tert.-butyl ester in 20 ml. of a 9:1-mixture of acetic acid and water is treated over the course of 3 /2 hours with small quantities of a total of 4 g. of zinc at room temperature and is then mixed with 20 ml. of water, and the mixture is filtered through cottonwool. Extraction is carried out three times with 30 ml. of methylene chloride each time. The organic extracts are dried over sodium sulphate and evaporated, acetic acid residues being removed azeotropically together with the benzene under reduced pressure; the latter operation is repeated 5 times. The residue is filtered through a silica gel column (1.8 cm. diameter; 5.5 cm. height), elution being carried out with a 1: l-mixture of hexane and ethyl acetate and finally with ethyl acetate. A lzl-mixture of the isomers of a-(2-carbortert.-butyloxy-3,3-dimethyl-7- oxo 4 thia 2,6 diaza-6-bicyclo[3,2,0]heptyl)-u-(carboxymethyl)-acetic acid tert.-butyl ester is thus obtained. Crystallization from a mixture of ether and hexane at room temperature yields isomer A, which after recrystallization from hexane at 0, melts at 169-173 (analytical sample: 172-173); [oz] 295i-1 (c. =l.168 in chloroform); thin layer chromatogram (silica gel): Rf=0.35 in a 5 :4:l-mixture of toluene, acetic acid and water; infrared absorption spectrum (in methylene chloride): characteristic bands at 5.68 5.72,u. and 5.90n.

The mother liquor from the above crystallization of the isomer mixture is concentrated and allowed to stand for 16 hours at room temperature, whereupon a further quantity of the isomer A is obtained. The filtrate is evaporated and recrystallized from hexane (0; 7 days); isomer B is thus obtained, M.-P. 116-117;

(c.=0.924 in chloroform); thin layer chromatogram (silica gel); Rf=0.350.33 in a 5:4: l-mixture of toluene, acetic acid and water; infrared absorption spectrum (in methylene chloride): characteristic bands at 5.68 t, 5.78 and 5.85-5.90

The resolution of 0.583 g. of the mixture of isomers of a-(2 carbo-tert.-butyloxy-3,3-dimethyl-7-oxo-4-thia- 2,6-diaza 6 bicyclo[3,2,0]heptyl)-a-(carboxymethyl)- acetic acid tert.-butyl ester can also be carried out chromatographically on acid-washed silica gel (column: 3 cm. diameter; and 35 cm. height), with 300 ml. of a 49:1-mixture, 300 ml. of a 19:1-mixture, 450 ml. of a 9:1- mixture, 300 ml. of a 4:1-mixture, 300 ml. of a 3: l-mixture, 300 ml. of a 2:1-mixture and 300 ml. of a lzl-mixture of hexane and ethyl acetate and 400 ml. of ethyl acetate being used as elution liquids. Isomer A is eluted with the 3:1- and the 2:1-mixture before isomer B and melts at 172-173 after crystallization from hexane.

An almost complete separation of the two isomers A and B of a-(2-carbo-tert.-butyloxy 3,3 dimethyl-7-oxo- 4-thia 2,6 diaza 6 bicyclo[3,2,0]heptyl)-u-(carboxymethyl)-acetic acid tert.-butyl ester can, for example, also be carried out by mixing 0.1 g. of the lzl-isomer mixture in 3 ml. of methylene chloride with 1.16 ml. of a ml. solution of 1.9836 g. of cyclohexylamine in ether (1 equivalent). The main portion of the isomer A precipitates as a gel and is shaken with 2 ml. of methylene chloride and 1.2 ml. of water containing 0.12 ml. of 2 N aqueous sulphuric acid. The organic phase is washed with 2.5 ml. of water and the aqueous phase with 2.5 ml. of methylene chloride; the organic extracts are combined, dried over sodium sulphate and evaporated; a 7: l-mixture of the isomers A and B is thus obtained.

EXAMPLE 38 A mixture of 0.027 g. of the isomer A of a-(2-carbotert.-butyloxy 3,3 dimethyl 7 oxo 4 thia 2,6- diazo 6 bicyclo[3,2,0]heptyl) on (carboxymethyl)- acetic acid tert.-butyl ester and 1 ml. of precooled trifiuoroacetic acid is kept for 30 minutes at -10 and is then evaporated at 10 under a high vacuum and mixed with 10 ml. of ether. The solution is washed once with 4 ml. and once with 1 ml. of a saturated aqueous sodium hydrogen carbonate solution and is then mixed with 4 ml. of a saturated phosphate buffer solution (pH 6) and adjusted to pH 5-6 with 3.75 ml. of 2 N aqueous sulphuric acid. The mixture is extracted twice with 10 ml. of ether each time and the organic phase is once washed with 2 ml. of water, dried over sodium sulphate and evaporated. The noncrystalline isomer A of a-(3,3-dimethyl- 7-oxo-4-thia 2,6 diaza 6 bicyclo[3,2,0]heptyl)-a- (carboxymethyl)-acetic acid tert.-butyl ester of the formula CO 0C (CH3):

CH:C O OH err-43 HN S H: C CH;

is thus obtained and has an Rf=0.31 in a thin layer chromatogram (silica gel) in a 5:5:1-mixture of toluene, acetic acid and water.

EXAMPLE 39 A mixture of 0.105 g. of the isomer B of a-(Z-carbotert.-butyloxy 3,3 dimethyl 7 oxo 4 thia 2,6- diaza 6 bicyclo[3,2,0]heptyl) a (carboxymethyl)- acetic acid tert.-butyl ester and 2.5 ml. of trifiuoroacetic acid pre-cooled to -8 is kept for 35 minutes at 10 and is then evaporated under a high vacuum. The crude product is mixed with 40 ml. of a 1:1-mixture of a saturated aqueous sodium hydrogen carbonate solution and ether at 0; the ether phase is washed with 5 ml. of a saturated aqueous sodium hydrogen carbonate solution and 5 ml. of water, then treated with 3 ml. of a concentrated phosphate buffer solution (pH 6) and adjusted to pH 5-6 with 2 N aqueous sulphuric acid, and then extracted three times with 15 ml. of ether each time. The combined ether solutions are washed with 5 ml. of water, dried over sodium sulphate and evaporated. After recrystallization from a mixture of ether, methylene chloride and hexane, the isomer B of u-(3,3-dimethyl-7-oxo- 4-thia 2,6 diaza 6 bicyclo[3,2,0]heptyl) a. (carboxymethyl)acetic acid tert.-butyl ester is obtained, M.P. 137138; [u] =-l07:1 (c.=0.7 in chloroform); infrared absorption spectrum (in methylene chloride): characteristic bands at 5.70 5.78 7.30;. and 8.70 4. 

